Aqueous Methods for Titanating A Chromium/Silica Catalyst

ABSTRACT

Methods for synthesizing a water-soluble titanium-silicon complex are disclosed herein. The titanium-silicon complex can be utilized to produce titanated solid oxide supports and titanated chromium supported catalysts. The titanated chromium supported catalysts subsequently can be used to polymerize olefins to produce, for example, ethylene based homopolymer and copolymers.

FIELD OF THE INVENTION

The present disclosure generally relates to titanated chromiumcatalysts, methods for preparing the titanated chromium catalysts,methods for using the titanated chromium catalysts to polymerizeolefins, the polymer resins produced using such chromium catalysts, andarticles produced using these polymer resins. More particularly, thepresent disclosure relates to methods for making a water-solubletitanium-silicon complex, and the subsequent use of the titanium-siliconcomplex to produce titanated solid oxide supports and titanated chromiumsupported catalysts.

BACKGROUND OF THE INVENTION

Chromium/silica-titania catalysts can be used to make HDPE. The additionof titanium to chromium/silica can increase the activity of thecatalyst, but more importantly, can increase the melt index potential ofthe catalyst, i.e., the ability of the catalyst to produce higher meltindex or higher melt flow polymers. Often, titanium addition has beenaccomplished via an anhydrous route, using titanium alkoxidesimpregnated onto chromium/silica from a suitable organic solvent, suchas a hydrocarbon, an alcohol, or an ether. This anhydrous route requiressubjecting the silica to a prolonged drying step at elevatedtemperatures to remove adsorbed moisture, which could react with thetitanium alkoxide and prevent it from attaching to the silica. Further,after titanium deposition, another prolonged drying step is needed toremove organics from the solvent and the alkoxide (e.g., resulting inVOC emissions). Melt index potential also can be lost during this dryingstep. For at least these reasons, the anhydrous process is performedbatchwise, which can further increase cost and reduce efficiency.

In view of these drawbacks, it would be beneficial to provide improvedmethods for making titanated chromium catalysts. It is to this end thatthe present invention is generally directed.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

In one aspect of this invention, a process for producing a water-solubletitanium complex is disclosed, and in this aspect, the process cancomprise (1) contacting a silicon compound with water and an acid or abase in a solvent to form a first solution containing apartially-hydrolyzed silicon material, and (2) contacting a titaniumcompound with the first solution containing the partially-hydrolyzedsilicon material to form a second solution containing a titanium-siliconcomplex.

In another aspect of this invention, a process for producing a titanatedsolid support is disclosed, and in this aspect, the process can comprise(1) contacting a silicon compound with water and an acid or a base in asolvent to form a first solution containing a partially-hydrolyzedsilicon material, (2) contacting a titanium compound with the firstsolution containing the partially-hydrolyzed silicon material to form asecond solution containing a titanium-silicon complex, and (3) combiningat least a portion of the second solution containing thetitanium-silicon complex, a solid support, and optional additionalwater, and drying to form the titanated solid support. Further, achromium-containing compound can be added during any of steps (1)-(3),thus resulting in a titanated chromium supported catalyst.

In yet another aspect of this invention, a process for producing atitanated chromium supported catalyst is disclosed, and in this aspect,the process can comprise (1) contacting a silicon compound with waterand an acid or a base in a solvent to form a first solution containing apartially-hydrolyzed silicon material, (2) contacting a titaniumcompound with the first solution containing the partially-hydrolyzedsilicon material to form a second solution containing a titanium-siliconcomplex, and (3) combining at least a portion of the second solutioncontaining the titanium-silicon complex, a supported chromium catalyst,and optional additional water, and drying to form the titanated chromiumsupported catalyst.

Titanated chromium supported catalysts also are disclosed and describedherein. For example, the titanated chromium supported catalyst cancomprise a solid support and from about 0.1 to about 15 wt. % chromium,from about 1 to about 10 wt. % titanium, and less than or equal to about3 wt. % carbon. These weight percentages are based on the total weightof the catalyst. Generally, at least about 75 wt. % of the chromium ispresent in an oxidation state of three or less.

The present invention also contemplates and encompasses olefinpolymerization processes. Such processes can comprise contacting anactivated titanated chromium supported catalyst and an optionalco-catalyst with an olefin monomer and optionally an olefin comonomer ina polymerization reactor system under polymerization conditions toproduce an olefin polymer. Beneficially, the titanated chromiumsupported catalysts have higher melt index potential, allowing theproduction of olefin polymers having higher melt indices (lowermolecular weights); thus, the titanated chromium supported catalystsdisclosed herein can be capable of producing, or configured to produce,higher melt index polymers.

Both the foregoing summary and the following detailed descriptionprovide examples and are explanatory only. Accordingly, the foregoingsummary and the following detailed description should not be consideredto be restrictive. Further, features or variations may be provided inaddition to those set forth herein. For example, certain aspects may bedirected to various feature combinations and sub-combinations describedin the detailed description.

Definitions

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2^(nd) Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied. To the extent that any definitionor usage provided by any document incorporated herein by referenceconflicts with the definition or usage provided herein, the definitionor usage provided herein controls.

Herein, features of the subject matter are described such that, withinparticular aspects, a combination of different features can beenvisioned. For each and every aspect and each and every featuredisclosed herein, all combinations that do not detrimentally affect thecompounds, compositions, processes, or methods described herein arecontemplated with or without explicit description of the particularcombination. Additionally, unless explicitly recited otherwise, anyaspect or feature disclosed herein can be combined to describe inventivecompounds, compositions, processes, or methods consistent with thepresent disclosure.

Generally, groups of elements are indicated using the numbering schemeindicated in the version of the periodic table of elements published inChemical and Engineering News, 63(5), 27, 1985. In some instances, agroup of elements can be indicated using a common name assigned to thegroup; for example, alkali metals for Group 1 elements, alkaline earthmetals for Group 2 elements, transition metals for Group 3-12 elements,and halogens or halides for Group 17 elements.

The term “hydrocarbon” whenever used in this specification and claimsrefers to a compound containing only carbon and hydrogen, whethersaturated or unsaturated. Other identifiers can be utilized to indicatethe presence of particular groups in the hydrocarbon (e.g., halogenatedhydrocarbon indicates the presence of one or more halogen atomsreplacing an equivalent number of hydrogen atoms in the hydrocarbon).The term “hydrocarbyl group” is used herein in accordance with thedefinition specified by IUPAC: a univalent group formed by removing ahydrogen atom from a hydrocarbon (that is, a group containing onlycarbon and hydrogen). Non-limiting examples of hydrocarbyl groupsinclude alkyl, alkenyl, aryl, and aralkyl groups, amongst other groups.

For any particular compound or group disclosed herein, any name orstructure (general or specific) presented is intended to encompass allconformational isomers, regioisomers, stereoisomers, and mixturesthereof that can arise from a particular set of substituents, unlessotherwise specified. The name or structure (general or specific) alsoencompasses all enantiomers, diastereomers, and other optical isomers(if there are any) whether in enantiomeric or racemic forms, as well asmixtures of stereoisomers, as would be recognized by a skilled artisan,unless otherwise specified. For instance, a general reference to pentaneincludes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane; and ageneral reference to a butyl group includes a n-butyl group, a sec-butylgroup, an iso-butyl group, and a t-butyl group.

Unless otherwise specified, the term “substituted” when used to describea group, for example, when referring to a substituted analog of aparticular group, is intended to describe any non-hydrogen moiety thatformally replaces a hydrogen in that group, and is intended to benon-limiting. Also, unless otherwise specified, a group or groups canalso be referred to herein as “unsubstituted” or by equivalent termssuch as “non-substituted,” which refers to the original group in which anon-hydrogen moiety does not replace a hydrogen within that group.Moreover, unless otherwise specified, “substituted” is intended to benon-limiting and include inorganic substituents or organic substituentsas understood by one of ordinary skill in the art.

The terms “contacting” and “combining” are used herein to describecompositions, processes, and methods in which the materials orcomponents are contacted or combined together in any order, in anymanner, and for any length of time, unless otherwise specified. Forexample, the materials or components can be blended, mixed, slurried,dissolved, reacted, treated, compounded, or otherwise contacted orcombined in some other manner or by any suitable method or technique.

In this disclosure, while compositions, processes, and methods aredescribed in terms of “comprising” various components or steps, thecompositions, processes, and methods also can “consist essentially of”or “consist of” the various components or steps, unless statedotherwise.

The terms “a,” “an,” and “the” are intended to include pluralalternatives, e.g., at least one. For instance, the disclosure of “asolid support,” “a chromium-containing compound,” etc., is meant toencompass one, or mixtures or combinations of more than one, solidsupport, chromium-containing compound, etc., unless otherwise specified.

The term “polymer” is used herein generically to include olefinhomopolymers, copolymers, terpolymers, and the like, as well as alloysand blends thereof. The term “polymer” also includes impact, block,graft, random, and alternating copolymers. A copolymer can be derivedfrom an olefin monomer and one olefin comonomer, while a terpolymer canbe derived from an olefin monomer and two olefin comonomers.Accordingly, “polymer” encompasses copolymers and terpolymers.Similarly, the scope of the term “polymerization” includeshomopolymerization, copolymerization, and terpolymerization. Therefore,an ethylene polymer would include ethylene homopolymers, ethylenecopolymers (e.g., ethylene/α-olefin copolymers), ethylene terpolymers,and the like, as well as blends or mixtures thereof. Thus, an ethylenepolymer encompasses polymers often referred to in the art as LLDPE(linear low density polyethylene) and HDPE (high density polyethylene).As an example, an ethylene copolymer can be derived from ethylene and acomonomer, such as 1-butene, 1-hexene, or 1-octene. If the monomer andcomonomer were ethylene and 1-hexene, respectively, the resultingpolymer could be categorized an as ethylene/1-hexene copolymer. The term“polymer” also includes all possible geometrical configurations, ifpresent and unless stated otherwise, and such configurations can includeisotactic, syndiotactic, and random symmetries. The term “polymer” alsois meant to include all molecular weight polymers, and is inclusive oflower molecular weight polymers or oligomers.

The terms “catalyst composition,” “catalyst mixture,” “catalyst system,”and the like, do not depend upon the actual product or compositionresulting from the contact or reaction of the initial components of thedisclosed or claimed catalyst composition/mixture/system, the nature ofthe active catalytic site, or the fate of the co-catalyst or thetitanated chromium supported catalyst after combining these components.Therefore, the terms “catalyst composition,” “catalyst mixture,”“catalyst system,” and the like, encompass the initial startingcomponents of the composition, as well as whatever product(s) may resultfrom contacting these initial starting components, and this is inclusiveof both heterogeneous and homogenous catalyst systems or compositions.The terms “catalyst composition,” “catalyst mixture,” “catalyst system,”and the like, may be used interchangeably throughout this disclosure.

A “water-soluble” material is meant to indicate that the material isdissolved in water at standard temperature (25° C.) and pressure (1atm); in this regard, there is no visual precipitation of the materialin water. Likewise, a “solution” is meant to indicate that there is novisual precipitate at standard temperature and pressure.

Various numerical ranges are disclosed herein. When a range of any typeis disclosed or claimed, the intent is to disclose or claim individuallyeach possible number that such a range could reasonably encompass,including end points of the range as well as any sub-ranges andcombinations of sub-ranges encompassed therein, unless otherwisespecified. As a representative example, the present disclosure recitesthat the molar ratio of titanium to silicon (Ti:Si) consistent withaspects of step (2) of this invention can be in a range from about 0.1:1to about 5:1. By a disclosure that the molar ratio of Ti:Si can be in arange from about 0.1:1 to about 5:1, the intent is to recite that theratio can be any ratio in the range and, for example, can be equal toabout 0.1:1, about 0.2:1, about 0.3:1, about 0.4:1, about 0.5:1, about0.6:1, about 0.7:1, about 0.8:1, about 0.9:1, about 1:1, about 2:1,about 3:1, about 4:1, or about 5:1. Additionally, the molar ratio can bewithin any range from about 0.1:1 to about 5:1 (e.g., from about 0.3:1to about 1:1), and this also includes any combination of ranges betweenabout 0.1:1 and about 5:1 (e.g., the ratio can be in a range from about0.2:1 to about 0.7:1, or from about 2:1 to about 4:1). Likewise, allother ranges disclosed herein should be interpreted in a manner similarto this example.

The term “about” means that amounts, sizes, formulations, parameters,and other quantities and characteristics are not and need not be exact,but can be approximate including being larger or smaller, as desired,reflecting tolerances, conversion factors, rounding off, measurementerrors, and the like, and other factors known to those of skill in theart. In general, an amount, size, formulation, parameter or otherquantity or characteristic is “about” or “approximate” whether or notexpressly stated to be such. The term “about” also encompasses amountsthat differ due to different equilibrium conditions for a compositionresulting from a particular initial mixture. Whether or not modified bythe term “about,” the claims include equivalents to the quantities. Theterm “about” can mean within 10% of the reported numerical value, andoften within 5% of the reported numerical value.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices, and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein are processes for preparing water-solubletitanium-silicon complexes and the use of such titanium-siliconcomplexes to prepare titanated solid oxide supports and titanatedchromium supported catalysts. Advantageously, the steps used to preparethese materials can be conducted in water-based systems, thuseliminating prolonged drying steps. For instance, the titanated solidoxide supports and titanated chromium supported catalysts can be simplydried via spray drying or other suitable technique. Moreover, theprocesses can be performed in a continuous manner, and are not limitedto batchwise production.

While not wishing to be bound by the following theory, it is believedthat there are few known water-soluble titanium compounds, such asTiOSO₄, and these cannot be used in conventional methods to titanatechromium supported catalysts, such as chromium/silica. The titanium canbe deposited, but not in a way that increases the melt index potentialof the catalyst. It is believed that separate TiO₂ domains form ratherthan an intimate dispersion or impregnation on the silica to generateacidic sites (to which the chromium can then attach). The typicaltitanium alkoxides, acetylacetonates, or halides all hydrolyze uponcontact with water, which can render them unusable for traditionaltitanation in a water-based system.

In contrast, the titanium complexes disclosed and described herein canbe soluble in water, but are still effective as titanation agents.Generally, this can be accomplished by combining titanium and silicon ina solution (i.e., with no visible precipitation), so that when it isdesired to deposit titanium onto a solid support or a catalyst, thetitanium is already attached to silicon.

Processes for Forming Water-Soluble Titanium Complexes

Aspects of this invention are directed to a process for forming awater-soluble titanium complex. One such process can comprise (orconsist essentially of, or consist of) (1) contacting a silicon compoundwith water and an acid or a base in a solvent to form a first solutioncontaining a partially-hydrolyzed silicon material, and (2) contacting atitanium compound with the first solution containing thepartially-hydrolyzed silicon material to form a second solutioncontaining a titanium-silicon complex.

Generally, the features of this process (e.g., the silicon compound, theacid or base, the solvent, the titanium compound, the conditions underwhich the partially-hydrolyzed silicon material is formed, and theconditions under which the titanium-silicon complex is formed, amongothers) are independently described herein and these features can becombined in any combination to further describe the disclosed process toproduce a titanium-silicon complex. Moreover, additional process stepscan be performed before, during, and/or after any of the steps in any ofthe processes disclosed herein, and can be utilized without limitationand in any combination to further describe these processes, unlessstated otherwise. Further, any water-soluble titanium-silicon complexesproduced in accordance with the disclosed processes are within the scopeof this disclosure and are encompassed herein.

In step (1), a silicon compound can be contacted with water and an acidor a base in a solvent to form a first solution containing apartially-hydrolyzed silicon material. In one aspect, the siliconcompound, water, the acid or the base, and the solvent can be contactedor combined together in any order, while in another aspect, the siliconcompound can be contacted first with the solvent, followed by additionof the acid or the base, and then water to form the first solution.

The relative amounts of water and the silicon compound are notparticularly limited, so long as the molecular size of thepartially-hydrolyzed silicon material, formed in step (1), does notinterfere with migration into the pores of the solid support and thesupported chromium catalyst in subsequent processing steps, discussedhereinbelow. Generally, if too much water is used in step (1), then SiO₂may precipitate, and the titanium compound can precipitate as TiO₂ instep (2), which is of no practical use. On the other hand, if the amountof water used is too little in step (1), the titanium compound may notreact sufficiently with the silicon material in step (2), andprecipitated TiO₂ can result. Therefore, typical ranges for the molarratio of water to silicon (H₂O:Si) in step (1) can include, but are notlimited to, from about 0.05:1 to about 1.95:1, from about 0.1:1 to about1.8:1, from about 0.2:1 to about 1.5:1, from about 0.3:1 to about 1.2:1,from about 0.05:1 to about 0.95:1, from about 0.1:1 to about 0.9:1, fromabout 0.2:1 to about 0.8:1, or from about 0.3:1 to about 0.7:1, and thelike.

The specific silicon compound used in step (1) is not particularlylimited. Representative and non-limiting examples of suitable siliconcompounds can include a silicon alkoxide (e.g., tetraethylorthosilicate), a silicon halide, a silicon hydride, a silane, ahydrocarbyl silane, a siloxane, and the like, as well as combinationsthereof. Likewise, any suitable solvent can be used in step (1), butoften the solvent is miscible with both oil and water. Representativeand non-limiting examples of suitable solvents for use in step (1) caninclude a ketone (e.g., acetone), an alcohol (e.g., methanol, ethanol,n-propanol, isopropanol, n-butanol, etc.), a glycol, an ester, an ether,acetonitrile, and the like. Additionally, combinations of two or moresolvents can be used.

The amount of the acid or base in step (1) is relatively small comparedto that of the solvent. For instance, the weight ratio of the acid orbase to the solvent (acid:solvent or base:solvent) often can be lessthan or equal to about 1:20; alternatively, less than or equal to about1:50; or alternatively, less than or equal to about 1:100. Illustrativeranges for the weight ratio acid:solvent or base:solvent can include,but are not limited to, from about 1:5000 to about 1:10, from about1:2000 to about 1:20, or from about 1:1000 to about 1:100, and the like.

When an acid is used in step (1), any suitable acid can be used,non-limiting examples of which include sulfuric acid, nitric acid,hydrochloric acid, hydrobromic acid, perchloric acid, sulfamic acid, andthe like, as well as any mixture or combination thereof. Similarly, whena base is used in step (1), any suitable base can be used, non-limitingexamples of which include ammonia, ammonium hydroxide, sodium hydroxide,magnesium hydroxide, an alkyl-substituted ammonium hydroxide, an organicamine, and the like, as well as any mixture or combination thereof.

Step (1) of the process, which forms a first solution containing apartially-hydrolyzed silicon material, can be conducted at any suitabletemperature and for any suitable period of time. Representative andnon-limiting ranges for the temperature of step (1) can include fromabout 5° C. to about 80° C., from about 15° C. to about 60° C., fromabout 10° C. to about 40° C., or from about 20° C. to about 50° C. Thesetemperature ranges also are meant to encompass circumstances where step(1) is performed at a series of different temperatures, instead of at asingle fixed temperature, falling within the respective temperatureranges.

Similarly, the time period for contacting the silicon compound, water,the acid or base, and the solvent (or for the formation of the firstsolution containing the partially-hydrolyzed silicon material) is notparticularly limited, and can be conducted for any suitable period oftime. In some aspects, the time period can be least about 1 minute, atleast about 5 minutes, at least about 10 minutes, at least about 15minutes, or at least about 30 minutes. In other aspects, the time periodcan be from about 30 seconds to about 48 hours, from about 1 minute toabout 24 hours, from about 5 minutes to about 8 hours, from about 15minutes to about 8 hours, or from about 5 minutes to about 2 hours.

Referring now to step (2), in which a titanium compound can be contactedwith the first solution containing the partially-hydrolyzed siliconmaterial to form a second solution containing a titanium-siliconcomplex. The relative amounts of the titanium compound and the siliconmaterial are not particularly limited, so long as significantprecipitation does not result (e.g., if the Ti:Si ratio becomes toolarge). However, typical ranges for the molar ratio of titanium tosilicon (Ti:Si) in step (2) can include, but are not limited to, fromabout 0.1:1 to about 5:1, from about 0.1:1 to about 2:1, from about0.2:1 to about 3:1, from about 0.3:1 to about 2:1, from about 0.3:1 toabout 1:1, from about 0.3:1 to about 0.8:1, from about 0.3:1 to about0.7:1, or from about 0.2:1 to about 0.9:1, and the like.

The specific titanium compound used in step (2) is not particularlylimited. Consistent with certain aspects of this invention, the titaniumcompound can be a Ti (III) compound and/or a Ti (IV) compound.Representative and non-limiting examples of suitable titanium compoundscan include a titanium alkoxide (e.g., titanium isopropoxide, titaniumn-propoxide), a titanium halide, a titanium carboxylate, a titaniumacetylacetonate, and the like, as well as combinations thereof.

Step (2) of the process, which forms a second solution containing atitanium-silicon complex, can be conducted at any suitable temperatureand for any suitable period of time. Representative and non-limitingranges for the temperature of step (2) can include from about 5° C. toabout 80° C., from about 15° C. to about 60° C., from about 10° C. toabout 40° C., or from about 20° C. to about 50° C. These temperatureranges also are meant to encompass circumstances where step (2) isperformed at a series of different temperatures, instead of at a singlefixed temperature, falling within the respective temperature ranges.

Similarly, the time period for contacting the titanium compound with thefirst solution containing the partially-hydrolyzed silicon material (orfor the formation of the second solution containing a titanium-siliconcomplex) is not particularly limited, and can be conducted for anysuitable period of time. In some aspects, the time period can be leastabout 1 minute, at least about 5 minutes, at least about 10 minutes, atleast about 15 minutes, or at least about 30 minutes. In other aspects,the time period can be from about 30 seconds to about 48 hours, fromabout 1 minute to about 24 hours, from about 5 minutes to about 8 hours,from about 15 minutes to about 8 hours, or from about 5 minutes to about2 hours.

In particular aspects of this invention, the second solution containingthe titanium-silicon complex does not contain a precipitate.Accordingly, the aforementioned process—step (1) and step (2)—canproduce a “partially hydrolyzed” water-soluble titanium-silicon complex.

Yet, in other aspects, the process—step (1) and step (2)—can furthercomprise a step of combining additional water and at least a portion ofthe second solution containing the titanium-silicon complex to form a“fully hydrolyzed” water-soluble titanium-silicon complex. The amount ofadditional water that is added is not particularly limited, butgenerally is an amount sufficient for complete hydrolysis of thetitanium-silicon complex. Representative and non-limiting ranges for themolar ratio of the amount of additional water to silicon (H₂O:Si) in thecombining step can be at least about 1:1, at least about 1.5:1, at leastabout 2:1, at least about 4:1, at least about 7:1, at least about 10:1,at least about 20:1, or at least about 100:1, and the like.

Consistent with aspects of this invention, the partially-hydrolyzedsilicon materials of step (1) and the titanium-silicon complexes of step(2), independently, can have (or can be configured to have) molecularsizes sufficient to allow migration into the pores of the solid supportand the supported chromium catalyst in subsequent processing steps,discussed hereinbelow. While not wishing to be bound by the followingtheory, it is believed that the molecular sizes can be significantlyless than 100 Å, and in some instances, from about 2 Å, about 5 Å, orabout 7 Å, up to about 15 Å, about 20 Å, or about 25 Å, while not beinglimited thereto.

Processes for Forming Titanated Solid Oxide Supports

In one aspect of this invention, a first process for producing atitanated solid support is disclosed, and in this aspect, the processcan comprise combining—in any order—the water-soluble titanium-siliconcomplex produced as described above (a partially-hydrolyzed orfully-hydrolyzed titanium-silicon complex), a solid support, andoptionally, additional water, and drying to form the titanated solidsupport.

In another aspect of this invention, a second process for producing atitanated solid support is disclosed, and in this aspect, the processcan comprise (or consist essentially of, or consist of) (1) contacting asilicon compound with water and an acid or a base in a solvent to form afirst solution containing a partially-hydrolyzed silicon material, (2)contacting a titanium compound with the first solution containing thepartially-hydrolyzed silicon material to form a second solutioncontaining a titanium-silicon complex, and (3) combining—in any order—atleast a portion of the second solution containing the titanium-siliconcomplex, a solid support, and optionally, additional water, and dryingto form the titanated solid support.

Generally, the features of the first and second process to produce thetitanated solid support (e.g., the titanium-silicon complex, the solidsupport, the additional water that is added (if any), and the conditionsunder which the titanated solid support is formed, among others) areindependently described herein and these features can be combined in anycombination to further describe the disclosed processes to produce atitanated solid support. Moreover, additional process steps can beperformed before, during, and/or after any of the steps in any of theprocesses disclosed herein, and can be utilized without limitation andin any combination to further describe the first and second process forproducing a titanated solid support, unless stated otherwise. Further,any titanated solid supports produced in accordance with the disclosedprocesses are within the scope of this disclosure and are encompassedherein.

In the first and second process for producing a titanated solid support,when additional water is used, the titanium-silicon complex, the solidsupport, and the additional water can be combined in any order orsequence. For example, the titanium-silicon complex can be combinedfirst with the solid support, followed by the additional water.Alternatively, the titanium-silicon complex can be combined first withthe additional water, followed by the solid support. The components inthe combining step can be contacted or combined by any suitable means,such as by mixing or slurrying the components.

In circumstances where additional water is added, the relative amount ofthe additional water and the titanium-silicon compound are notparticularly limited, but generally, the amount of additional wateradded can be an amount sufficient for complete hydrolysis of thetitanium-silicon complex. Representative and non-limiting ranges for themolar ratio of the amount of additional water to silicon (H₂O:Si) in thecombining step can be at least about 1:1, at least about 1.5:1, at leastabout 2:1, at least about 4:1, at least about 7:1, at least about 10:1,at least about 20:1, or at least about 100:1, and the like.

The combining step of the process, which forms a titanated solidsupport, can be conducted at any suitable temperature and for anysuitable period of time. Representative and non-limiting ranges for thetemperature of the combining step can include from about 5° C. to about80° C., from about 15° C. to about 60° C., from about 10° C. to about40° C., or from about 20° C. to about 50° C. These temperature rangesalso are meant to encompass circumstances where the combining step isperformed at a series of different temperatures, instead of at a singlefixed temperature, falling within the respective temperature ranges.

Similarly, the time period for contacting additional water (if used),the water-soluble titanium-silicon complex, and the solid support (orfor the formation of the titanated solid support) is not particularlylimited, and can be conducted for any suitable period of time. In someaspects, the time period can be least about 1 minute, at least about 5minutes, at least about 10 minutes, at least about 15 minutes, or atleast about 30 minutes. In other aspects, the time period can be fromabout 30 seconds to about 48 hours, from about 1 minute to about 24hours, from about 5 minutes to about 8 hours, from about 15 minutes toabout 8 hours, or from about 5 minutes to about 2 hours.

In particular aspects of this invention, the combining step does notresult in precipitation of the titanium-silicon complex.

Any suitable solid oxide can be used as the solid support. Generally,the solid oxide can comprise oxygen and one or more elements selectedfrom Group 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 of theperiodic table, or comprise oxygen and one or more elements selectedfrom the lanthanide or actinide elements (See: Hawley's CondensedChemical Dictionary, 11^(th) Ed., John Wiley & Sons, 1995; Cotton, F.A., Wilkinson, G., Murillo, C. A., and Bochmann, M., Advanced InorganicChemistry, 6^(th) Ed., Wiley-Interscience, 1999). For example, the solidinorganic oxide can comprise oxygen and an element, or elements,selected from Al, B, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Mo, Ni, Sb,Si, Sn, Sr, Th, Ti, V, W, P, Y, Zn, and Zr. Illustrative examples ofsolid oxide materials or compounds that can be used as solid support caninclude, but are not limited to, Al₂O₃, B₂O₃, BeO, Bi₂O₃, CdO, Co₃O₄,Cr₂O₃, CuO, Fe₂O₃, Ga₂O₃, La₂O₃, Mn₂O₃, MoO₃, NiO, P₂O₅, Sb₂O₅, SiO₂,SnO₂, SrO, ThO₂, TiO₂, V₂O₅, WO₃, Y₂O₃, ZnO, ZrO₂, and the like,including mixed oxides thereof, and combinations thereof.

The solid support can encompass oxide materials such as alumina, “mixedoxide” compounds thereof such as silica-alumina, and combinations ormixtures of more than one solid oxide material. Mixed oxides such assilica-alumina can be single or multiple chemical phases with more thanone metal combined with oxygen to form the solid oxide. Examples ofmixed oxides that can be used as solid support include, but are notlimited to, silica-alumina, silica-coated alumina, silica-titania,silica-zirconia, alumina-titania, alumina-zirconia, zinc-aluminate,alumina-boria, silica-boria, aluminum phosphate, aluminophosphate,aluminophosphate-silica, titania-zirconia, and the like, or acombination thereof. In some aspects, the solid support can comprisesilica, silica-alumina, silica-coated alumina, silica-titania,silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria,aluminophosphate-silica, and the like, or any combination thereof.Silica-coated aluminas are encompassed herein; such oxide materials aredescribed in, for example, U.S. Pat. No. 7,884,163, the disclosure ofwhich is incorporated herein by reference in its entirety.

The percentage of each oxide in a mixed oxide can vary depending uponthe respective oxide materials. As an example, a silica-aluminatypically has an alumina content from 5 wt. % to 95 wt. %. According toone aspect, the alumina content of the silica-alumina can be from 5 wt.% alumina 50 wt. % alumina, or from 8 wt. % to 30 wt. % alumina. Inanother aspect, high alumina content silica-alumina compounds can beemployed, in which the alumina content of these silica-alumina materialstypically ranges from 60 wt. % alumina to 90 wt. % alumina, or from 65wt. % alumina to 80 wt. % alumina.

In one aspect, the solid support can comprise silica-alumina,silica-coated alumina, silica-titania, silica-zirconia, alumina-titania,alumina-zirconia, zinc-aluminate, alumina-boria, silica-boria, aluminumphosphate, aluminophosphate, aluminophosphate-silica, titania-zirconia,or a combination thereof alternatively, silica-alumina; alternatively,silica-coated alumina; alternatively, silica-titania; alternatively,silica-zirconia; alternatively, alumina-titania; alternatively,alumina-zirconia; alternatively, zinc-aluminate; alternatively,alumina-boria; alternatively, silica-boria; alternatively, aluminumphosphate; alternatively, aluminophosphate; alternatively,aluminophosphate-silica; or alternatively, titania-zirconia.

In another aspect, the solid oxide can comprise silica, alumina,titania, zirconia, magnesia, boria, zinc oxide, a mixed oxide thereof,or any mixture thereof. In yet another aspect, the solid support cancomprise silica, alumina, titania, or a combination thereofalternatively, silica; alternatively, alumina; alternatively, titania;alternatively, zirconia; alternatively, magnesia; alternatively, boria;or alternatively, zinc oxide. In still another aspect, the solid supportcan comprise silica, alumina, silica-alumina, silica-coated alumina,aluminum phosphate, aluminophosphate, heteropolytungstate, titania,zirconia, magnesia, boria, zinc oxide, silica-titania, silica-zirconia,alumina-titania, alumina-zirconia, zinc-aluminate, alumina-boria,silica-boria, aluminophosphate-silica, titania-zirconia, and the like,or any combination thereof.

Additionally, the solid support can comprise a zeolite. Any suitablezeolite can be used, for instance, large pore and medium pore zeolites.Large pore zeolites often have average pore diameters in a range of fromabout 7 Å to about 12 Å, and non-limiting examples of large porezeolites include L-zeolite, Y-zeolite, mordenite, omega zeolite, betazeolite, and the like. Medium pore zeolites often have average porediameters in a range of from about 5 Å to about 7 Å. The term “zeolite”generally refers to a particular group of hydrated, crystalline metalaluminosilicates. These zeolites exhibit a network of SiO₄ and AlO₄tetrahedra in which aluminum and silicon atoms are crosslinked in athree-dimensional framework by sharing oxygen atoms. In the framework,the ratio of oxygen atoms to the total of aluminum and silicon atoms canbe equal to 2. The framework exhibits a negative electrovalence thattypically can be balanced by the inclusion of cations within thecrystal, such as metals, alkali metals, alkaline earth metals, and/orhydrogen.

In some aspects, the solid support can comprise an L-type zeolite.L-type zeolite supports are a sub-group of zeolitic supports, which cancontain mole ratios of oxides in accordance with the formula:M_(2/n)OAl₂O₃xSiO₂yH₂O. In this formula, “M” designates an exchangeablecation (one or more) such as barium, calcium, cerium, lithium,magnesium, potassium, sodium, strontium, cesium, and/or zinc, as well asnon-metallic cations like hydronium and ammonium ions, which can bereplaced by other exchangeable cations without causing a substantialalteration of the basic crystal structure of the L-type zeolite. The “n”in the formula represents the valence of “M”; “x” is 2 or greater; and“y” is the number of water molecules contained in the channels orinterconnected voids of the zeolite.

The process disclosed herein for producing titanated solid supports, andtitanated solid supports produced by the processes disclosed herein, arenot limited to any particular amount of titanium. Often, the amount oftitanium in the titanated solid support can range from about 0.1 toabout 20 wt. %; alternatively, from about 0.5 to about 15 wt. %;alternatively, from about 1 to about 10 wt. %; or alternatively, fromabout 1 to about 6 wt. %. These weight percentages are based on theamount of titanium relative to the total weight of the titanated solidsupport.

The processes disclosed herein include a step of drying. Any method ortechnique for drying can be used. For instance, if no additional wateris added, the solid support can be combined (or impregnated) with thewater-soluble titanium-silicon complex to incipient wetness, wherein thepore filling or “incipient wetness” impregnation technique used is amethod in which an amount of the solution of the water-solubletitanium-silicon complex roughly equivalent to the pore volume of thesolid support is mixed with the solid support until the pores arefilled. In the incipient wetness impregnation technique, the solidsupport can be placed into a rotating drum, and the solution of thewater-soluble titanium-silicon complex can be poured, sprayed orotherwise uniformly added onto the solid support. The end point of thismethod can vary somewhat, so that the titanated solid support could havea free-flowing dry appearance to the first appearances of clumping.However, typically there would not be any free-flowing liquid presentwhen the incipient wetness method is employed. As would be recognized bythose of skill in the art, other suitable techniques and equipment canbe employed when no additional water is added, and such techniques andequipment are encompassed herein.

In aspects where no additional water is added, the drying step canencompass a wide range of drying times, drying temperatures, and dryingpressures. For example, the drying time can range from about 1 to about48 hours, from about 2 to about 24 hours, or from about 2 to about 12hours, and the drying temperature can range from about 15° C. to about200° C., from about 25° C. to about 150° C., or from about 50° C. toabout 125° C. The drying pressure can be at or around atmosphericpressure, but in many instances, the drying step can be conducted undervacuum conditions at any suitable sub-atmospheric pressure, such as lessthan 100 torr (13.3 kPa), less than 50 (6.67 kPa) torr, or less than 10torr (1.33 kPa).

Various types of dryer devices can be used for the drying step(typically when additional water has been added), such as tray dryers,rotary dryers, fluidized bed dryers, and spray dryers, although notlimited thereto. Likewise, the flow of the drying medium (gas flow)relative to the solid support is not particularly limited, andencompasses concurrent flow, countercurrent flow, and flow through(e.g., such as in a fluidized bed).

In some aspects of this invention, the drying step can comprise spraydrying. Generally, spray drying can be used to transform the wettitanated solid support (e.g., a slurry or suspension of the titanatedsolid support in water) to a dried particulate or powder form byspraying a feed stream containing the wet titanated solid support into adevice containing a hot drying gas (usually air), in which the residualwater evaporates from the titanated solid support.

In the spray drying process, the feed stream can be sprayed into adrying chamber in the form of droplets, and contacted with a largevolume of a hot gas, which directly contacts the wet solid support.Typical gas inlet temperatures range from 125° C. to about 800° C., orfrom about 150° C. to about 500° C., but are not limited thereto. Theflow of the gas relative to the flow of the solid support into the spraydryer can be concurrent flow, countercurrent flow, or mixed flow. Afterdrying, the gas stream and the dried titanated solid support areseparated. If needed, fines can be removed in filter collectors orcyclones. The dried titanated solid support can have the form offree-flowing particulate solids.

The initial feed into the spray dryer can be subjected to an atomizationprocess, which can employ, for instance, a high-pressure nozzle, atwo-fluid nozzle, or a high-speed centrifugal disk. High-pressurenozzles result in atomization by forcing the solid support slurry underhigh pressure through a small nozzle orifice, the size of which candepend on the desired pressure and particle size of the solids in theslurry, among other factors. Wear on the nozzle orifice and plugging canresult during long-term operation; therefore, regular maintenance can bebeneficial to ensure proper atomization. Two-fluid nozzles have theadvantage of a relatively low operating pressure, and often can be usedwhen the feed stream is a thick or high-solids slurry, which does notwork well in high-pressure nozzle systems. The atomizing fluid can besteam or air.

High-speed centrifugal disks atomize the solid support slurry bycontacting the slurry with a rapidly rotating disk. Disk diameter anddisk speed (e.g., 3,000 rpm and above) can be varied to produce asuitable droplet size for drying. Beneficially, disk atomization is notsubject to wear and plugging, as in the nozzle systems. Disk rotationcan be driven by any suitable motor or technique.

Regardless of the atomization process, the spray drying process can beconfigured to maintain the spherical nature of the titanated solidsupport. The average particle size of the solid support can bemaintained in many instances, and generally, the average particle sizedepends upon the atomization process, the solids content of the solidsupport feed stream, feed stream viscosity, and feed rate, among otherfactors. Likewise, bulk density of the dried titanated solid support canbe controlled based on operating conditions of the spray dryer, such asdroplet size, inlet gas temperature, and air turbulence, among otherfactors.

Mixing of the gas stream (e.g., air) and the droplet in the dryingchamber can be accomplished, for example, using concurrent flow of gasand solids (e.g., horizontal or vertical spray dryers), orcountercurrent flow of gas and solids. In the latter case, upward airflow can carry fines to the top of the chamber for easy removal. Mixedflow spray dryers combine countercurrent and concurrent drying, withcomplex flow patterns and high turbulence for efficient heat and masstransfer.

A benefit to spray drying can be the short contact time of the titanatedsolid support to elevated temperatures in the drying chamber. Thus, inaddition to average particle size, the spray drying process can beconfigured to produce dried titanated solid supports that have surfaceareas and pore volumes that are comparable to the starting material(i.e., prior to spray drying).

Optionally, after drying, the titanated solid support can be calcined,which can be conducted at a variety of temperatures and time periods.Typical peak calcining temperatures often fall within a range from about200° C. to about 800° C., such as from about 250° C. to about 600° C.,from about 300° C. to about 600° C., or from about 300° C. to about 500°C. In these and other aspects, these temperature ranges also are meantto encompass circumstances where the calcination step is conducted at aseries of different temperatures (e.g., an initial calcinationtemperature, a peak calcination temperature), instead of at a singlefixed temperature, falling within the respective ranges. For instance,the calcination step can start at an initial temperature that is thesame as the drying temperature in the drying step. Subsequently, thetemperature of the calcination can be increased to a peak calciningtemperature, for example, in a range from about 250° C. to about 600° C.

The duration of the calcining step is not limited to any particularperiod of time. Hence, the calcining step can be conducted, for example,in a time period ranging from as little as 30-45 minutes to as long as36-48 hours, or more. The appropriate calcining time can depend upon,for example, the initial/peak calcining temperature, among othervariables. Generally, however, the calcining step can be conducted in atime period that can be in a range from about 30 minutes to about 48hours, such as, for example, from about 1 hour to about 24 hours, fromabout 1 hour to about 12 hours, from about 2 hours to about 12 hours, orfrom about 2 hours to about 8 hours.

The calcining step can be conducted in a calcining gas stream thatcomprises (or consists essentially of, or consists of) an inert gas(e.g., nitrogen), oxygen, air, or any mixture or combination thereof. Insome aspects, the calcining gas stream can comprise air, while in otheraspects, the calcining gas stream can comprise a mixture of air andnitrogen. Yet, in certain aspects, the calcining gas stream can be aninert gas, such as nitrogen and/or argon.

The calcining step can be conducted using any suitable technique andequipment, whether batch or continuous. For instance, the calcining stepcan be performed in a belt calciner or, alternatively, a rotarycalciner. In some aspects, the calcining step can be performed in abatch or continuous calcination vessel comprising a fluidized bed. Aswould be recognized by those of skill in the art, other suitabletechniques and equipment can be employed for the calcining step, andsuch techniques and equipment are encompassed herein.

The pore volume of the titanated solid support is not particularlylimited. For instance, the titanated solid support can have a porevolume (total pore volume via mercury intrusion) in a range from about0.5 to about 5 mL/g, from about 1 to about 5 mL/g, from about 1 to about3 mL/g, or from about 1.2 to about 2.5 mL/g. Likewise, the surface areaof the titanated solid support is not limited to any particular range.Generally, however, the titanated solid support can have a BET surfacearea in a range from about 200 to about 700 m²/g, from about 100 toabout 600 m²/g, from about 250 to about 600 m²/g, from about 250 toabout 550 m²/g, or from about 275 to about 525 m²/g.

The titanated solid support can have any suitable particle size, aswould be recognized by those of skill in the art. Illustrative andnon-limiting ranges for the average (d50) particle size of the titanatedsolid support can include from about 10 to about 500 microns, from about25 to about 250 microns, from about 40 to about 160 microns, or fromabout 40 to about 120 microns.

Processes for Forming Titanated Chromium Catalysts

Aspects of this invention also are directed to processes for producingtitanated chromium supported catalysts. In the processes for producingtitanium-silicon complexes and for producing titanated solid supports,described hereinabove, chromium can be incorporated at any step in therespective processes. In one aspect, for example, chromium can be addedin step (1). In this aspect, step (1) can comprise contacting thesilicon compound, water, the acid or the base, and a chromium-containingcompound in the solvent. The components in step (1) can be contacted inany order or sequence. In another aspect, chromium can be added in step(2). In this aspect, step (2) can comprise contacting the titaniumcompound and a chromium-containing compound with the first solutioncontaining the partially-hydrolyzed silicon material. As above, thecomponents in step (2) can be contacted in any order or sequence. In yetanother aspect, chromium can be added in step (3). In this aspect, step(3) can comprise combining (in any order) a chromium-containingcompound, at least a portion of the second solution containing thetitanium-silicon complex, a solid support, and optionally, additionalwater, and drying. If the titanated solid support has already beenproduced, chromium can be incorporated by combining the titanated solidsupport and a chromium-containing compound, in water, and drying.Titanated chromium supported catalysts produced in accordance with anyof these processes are within the scope of this disclosure and areencompassed herein.

Any suitable chromium-containing compound (or chromium precursor) can beused to form the titanated chromium supported catalyst. Illustrative andnon-limiting examples of chromium (II) compounds can include chromium(II) acetate, chromium (II) chloride, chromium (II) bromide, chromium(II) iodide, chromium (II) sulfate, and the like, as well ascombinations thereof. Likewise, illustrative and non-limiting examplesof chromium (III) compounds can include a chromium (III) carboxylate, achromium (III) napthenate, a chromium (III) halide, chromium (III)sulfate, chromium (III) nitrate, a chromium (III) dionate, and the like,as well as combinations thereof. In some aspects, thechromium-containing compound can comprise chromium (III) acetate,chromium (III) acetylacetonate, chromium (III) chloride, chromium (III)bromide, chromium (III) sulfate, chromium (III) nitrate, and the like,as well combinations thereof.

While not required, it can be beneficial for the chromium-containingcompound to be soluble in the solvent, for instance, depending uponwhich step of the process is the chromium incorporation step. In suchsituations, the chromium-containing compound can comprise tertiary butylchromate, a diarene chromium (0) compound, bis-cyclopentadienyl chromium(II), chromium (III) acetylacetonate, chromium acetate, and the like, orany combination thereof.

Similarly, and not required, it can be beneficial for thechromium-containing compound to be soluble in water, for instance,depending upon which step of the process is the chromium incorporationstep. In such situations, the chromium-containing compound can comprisechromium trioxide, chromium acetate, chromium nitrate, and the like, orany combination thereof.

Consistent with other aspects of this invention, titanium can added to asupported chromium catalyst to produce a titanated chromium supportedcatalyst. One such process for producing a titanated chromium supportedcatalyst can comprise combining—in any order—the water-solubletitanium-silicon complex produced as described hereinabove (apartially-hydrolyzed or fully-hydrolyzed titanium-silicon complex), asupported chromium catalyst, and optionally, additional water, anddrying to form the titanated chromium supported catalyst.

Another process for producing a titanated chromium supported catalystcan comprise (or consist essentially of, or consist of) (1) contacting asilicon compound with water and an acid or a base in a solvent to form afirst solution containing a partially-hydrolyzed silicon material, (2)contacting a titanium compound with the first solution containing thepartially-hydrolyzed silicon material to form a second solutioncontaining a titanium-silicon complex, and (3) combining—in any order—atleast a portion of the second solution containing the titanium-siliconcomplex, a supported chromium catalyst, and optionally, additionalwater, and drying to form the titanated chromium supported catalyst.

Generally, the features of these processes to produce the titanatedchromium supported catalyst (e.g., the titanium-silicon complex, thesupported chromium catalyst, the additional water that is added (ifany), and the conditions under which the titanated chromium supportedcatalyst is formed, among others) are independently described herein andthese features can be combined in any combination to further describethe disclosed processes to produce a titanated chromium supportedcatalyst. Moreover, additional process steps can be performed before,during, and/or after any of the steps in any of the processes disclosedherein, and can be utilized without limitation and in any combination tofurther describe the processes for producing a titanated chromiumsupported catalyst, unless stated otherwise. Further, any titanatedchromium supported catalysts produced in accordance with the disclosedprocesses are within the scope of this disclosure and are encompassedherein.

In these processes for producing a titanated chromium supportedcatalyst, when additional water is used, the titanium-silicon complex,the supported chromium catalyst, and the additional water can becombined in any order or sequence. For example, the titanium-siliconcomplex can be combined first with the supported chromium catalyst,followed by the additional water. Alternatively, the titanium-siliconcomplex can be combined first with the additional water, followed by thesupported chromium catalyst. The components in the combining step can becontacted or combined by any suitable means, such as by mixing orslurrying the components.

In circumstances where additional water is added, the relative amount ofthe additional water and the titanium-silicon compound are notparticularly limited, but generally, the amount of additional wateradded can be an amount sufficient for complete hydrolysis of thetitanium-silicon complex. Representative and non-limiting ranges for themolar ratio of the amount of additional water to silicon (H₂O:Si) in thecombining step can be at least about 1:1, at least about 1.5:1, at leastabout 2:1, at least about 4:1, at least about 7:1, at least about 10:1,at least about 20:1, or at least about 100:1, and the like.

The combining step of the process, which forms a titanated chromiumsupported catalyst, can be conducted at any suitable temperature and forany suitable period of time. Representative and non-limiting ranges forthe temperature of the combining step can include from about 5° C. toabout 80° C., from about 15° C. to about 60° C., from about 10° C. toabout 40° C., or from about 20° C. to about 50° C. These temperatureranges also are meant to encompass circumstances where the combiningstep is performed at a series of different temperatures, instead of at asingle fixed temperature, falling within the respective temperatureranges.

Similarly, the time period for contacting additional water (if used),the water-soluble titanium-silicon complex, and the supported chromiumcatalyst (or for the formation of the titanated chromium supportedcatalyst) is not particularly limited, and can be conducted for anysuitable period of time. In some aspects, the time period can be leastabout 1 minute, at least about 5 minutes, at least about 10 minutes, atleast about 15 minutes, or at least about 30 minutes. In other aspects,the time period can be from about 30 seconds to about 48 hours, fromabout 1 minute to about 24 hours, from about 5 minutes to about 8 hours,from about 15 minutes to about 8 hours, or from about 5 minutes to about2 hours.

In particular aspects of this invention, the combining step does notresult in precipitation of the titanium-silicon complex.

Any suitable supported chromium catalyst can be used. Numerouscommercially-available grades of chromium catalyst, supported on varioussolid oxide supports, can be impregnated with titanium as disclosedherein. Often, the supported chromium catalyst can comprisechromium/silica, chromium/silica-titania,chromium/silica-titania-magnesia, chromium/silica-alumina,chromium/silica-coated alumina, chromium/aluminophosphate, and the like,or any combination thereof. In one aspect, the supported chromiumcatalyst can comprise chromium/silica, while in another aspect, thesupported chromium catalyst can comprise chromium/silica-titania. In yetanother aspect, the supported chromium catalyst can comprisechromium/silica-titania-magnesia; alternatively,chromium/silica-alumina; alternatively, chromium/silica-coated alumina;or alternatively, chromium/aluminophosphate.

The processes disclosed herein include a step of drying to form thetitanated chromium supported catalyst. Any method or technique fordrying can be used, such as the drying techniques disclosed hereinabove(e.g., spray drying) in relation to the titanated solid support.

In various aspects encompassed herein, the titanated chromium supportedcatalyst can be subjected to a thermal treatment step (often referred toas a calcining or activation step). The thermal treatment (orcalcination or activation) process can be conducted at a variety oftemperatures and time periods, which are generally selected to convertall or a portion of the chromium to hexavalent chromium. Often, thethermal treatment is performed in an oxidizing atmosphere, but this isnot a requirement. Activated titanated chromium supported catalystsproduced by such thermal treatment processes also are encompassed bythis invention.

In others aspects, the processes to form titanated solid supports, asdescribed above, can further comprises a step of contacting thetitanated solid support with a chromium-containingcompound—representative and non-limiting examples of thechromium-compound compound include chromium (III) acetate, basicchromium (III) acetate, chromium (III) acetylacetonate, Cr₂(SO₄)₃,Cr(NO₃)₃, and CrO₃—while thermally treating to form an activatedtitanated chromium supported catalyst. In these aspects, chromium can beimpregnated during the thermal treatment (or calcination or activation)process, which can be conducted at a variety of temperatures and timeperiods, and are generally selected to convert all or a portion of thechromium to hexavalent chromium. Similarly, activated titanated chromiumsupported catalysts produced by these thermal treatment processes (withconcurrent chromium addition) also are encompassed by this invention.

As noted above, thermal treatment (or calcining or activation) can beconducted at a variety of temperatures and time periods, which aregenerally selected to convert all or a portion of the chromium tohexavalent chromium. For instance, the thermal treatment step can beconducted at a peak temperature in a range from about 400° C. to about1000° C.; alternatively, from about 500° C. to about 900° C.; from about500° C. to about 900° C.; alternatively, from about 600° C. to about871° C.; alternatively, from about 550° C. to about 850° C.;alternatively, from about 700° C. to about 850° C.; alternatively, fromabout 725° C. to about 900° C.; alternatively, from about 725° C. toabout 871° C.; alternatively, from about 725° C. to about 850° C.;alternatively, from about 750° C. to about 871° C.; or alternatively,from about 750° C. to about 850° C. In these and other aspects, thesetemperature ranges also are meant to encompass circumstances where theactivation step is conducted at a series of different temperatures(e.g., an initial temperature, a peak temperature), instead of at asingle fixed temperature, falling within the respective ranges. Forinstance, the activation step can start at an initial temperature, andsubsequently, the temperature of the activation step can be increased tothe peak temperature, for example, a peak temperature in a range fromabout 550° C. to about 850° C., or from about 725° C. to about 900° C.

The duration of the thermal treatment step is not limited to anyparticular period of time. Hence, this thermal treatment step can beconducted, for example, in a time period ranging from as little as 1minute to as long as 12-24 hours, or more. The appropriate activationtime can depend upon, for example, the initial/peak temperature, amongother variables. Generally, however, the activation step can beconducted in a time period that can be in a range from about 1 minute toabout 24 hours, such as, for example, from about 30 minutes to about 8hours, from about 1 hour to about 12 hours, from about 2 hours to about12 hours, from about 3 hours to about 10 hours, or from about 5 hours toabout 10 hours.

In particular aspects of this invention, there can be substantially noVOC's (volatile organic compounds) emitted during the thermal treatment(calcination/activation) step. For instance, there can be substantiallyno VOC's emitted during the thermal treatment step when thetitanium-silicon complex is completely hydrolyzed. Thus, in accordancewith certain aspects of this invention, the titanated chromium supportedcatalyst (or activated titanated chromium supported catalyst) cancontain less than or equal to about 3 wt. % carbon, less than or equalto about 2.5 wt. % carbon, or less than or equal to about 2 wt. %carbon, and in further aspects, less than or equal to about 1 wt. %carbon, less than or equal to about 0.5 wt. % carbon, or less than orequal to about 0.25 wt. % carbon. These weight percentages are based onthe amount of carbon relative to the total weight of the respectivecatalyst.

The amount of titanium in the titanated chromium supported catalysts (oractivated titanated chromium supported catalysts) disclosed herein isnot particularly limited. Generally, however, the amount of titanium inthe titanated chromium supported catalyst (whether activated or not) canrange from about 0.1 to about 20 wt. %; alternatively, from about 0.5 toabout 15 wt. %; alternatively, from about 1 to about 10 wt. %;alternatively, from about 1 to about 6 wt. %; or alternatively, fromabout 1.5 to about 5 wt. % titanium. These weight percentages are basedon the amount of titanium relative to the total weight of the respectivecatalyst.

Likewise, the amount of chromium in the titanated chromium supportedcatalysts (or activated titanated chromium supported catalysts)disclosed herein is not particularly limited. Generally, however, theamount of chromium in the titanated chromium supported catalyst (whetheractivated or not) can range from about 0.1 to about 20 wt. %;alternatively, from about 0.1 to about 15 wt. %; alternatively, fromabout 0.5 to about 15 wt. %; alternatively, from about 0.5 to about 5wt. %; alternatively, from about 0.5 to about 2.5 wt. %; alternatively,from about 1 to about 10 wt. %; or alternatively, from about 1 to about6 wt. %. These weight percentages are based on the amount of chromiumrelative to the total weight of the respective catalyst.

The pore volume of the titanated chromium supported catalyst (oractivated titanated chromium supported catalyst) is not particularlylimited. For instance, the titanated chromium supported catalyst (oractivated titanated chromium supported catalyst) can have a pore volume(total pore volume via mercury intrusion) in a range from about 0.5 toabout 5 mL/g, from about 1 to about 5 mL/g, from about 1 to about 4mL/g, from about 1 to about 3 mL/g, or from about 1.2 to about 2.5 mL/g.Likewise, the surface area of the titanated chromium supported catalyst(or activated titanated chromium supported catalyst) is not limited toany particular range. Generally, however, the titanated chromiumsupported catalyst (or activated titanated chromium supported catalyst)can have a BET surface area in a range from about 200 to about 700 m²/g,from about 100 to about 600 m²/g, from about 250 to about 600 m²/g, 200to about 550 m²/g, from about 250 to about 550 m²/g, or from about 275to about 525 m²/g.

The titanated chromium supported catalyst (or activated titanatedchromium supported catalyst) can have any suitable particle size, aswould be recognized by those of skill in the art. Illustrative andnon-limiting ranges for the average (d50) particle size of the titanatedchromium supported catalyst (or activated titanated chromium supportedcatalyst) can include from about 10 to about 500 microns, from about 25to about 250 microns, from about 40 to about 160 microns, or from about40 to about 120 microns.

A representative and non-limiting example of a titanated chromiumsupported catalyst consistent with this invention can comprise a solidsupport and from about 0.1 to about 15 wt. % chromium, from about 1 toabout 10 wt. % titanium, and less than or equal to about 3 wt. % carbon(or any respective amount of chromium, titanium, and carbon disclosedherein). These weight percentages are based on the total weight of thecatalyst. Further, at least about 75 wt. % of the chromium is present inan oxidation state of three or less. While not wishing to be bound bythe following theory, it is believed that a titanated chromium supportedcatalyst having these characteristics, when subjected to a thermaltreatment step (calcination/activation), will no longer have thechromium in a lower oxidation state. Typically, all or a large portionof the chromium will be converted to hexavalent chromium.

Another representative and non-limiting example of a titanated chromiumsupported catalyst can comprise a solid support and from about 0.1 toabout 5 wt. % chromium (or from about 0.5 to about 2.5 wt. % chromium),from about 1 to about 6 wt. % titanium (or from about 1.5 to about 5 wt.% titanium), and less than or equal to about 2 wt. % carbon (or lessthan or equal to about 1 wt. % carbon, or less than or equal to about0.5 wt. % carbon). Further, at least about 80 wt. % (or at least about90 wt. %, or at least about 95 wt. %, or substantially all) of thechromium can be present in an oxidation state of three or less.

Thus, consistent with aspects of this invention, the amount of the solidsupport in the titanated chromium supported catalyst generally can rangefrom about 72 to about 98.5 wt. %; alternatively, from about 87 to about98 wt. %; alternatively, from about 92 to about 98 wt. %; alternatively,from about 93 to about 98 wt. %; or alternatively, from about 94 toabout 97 wt. % solid support. These weight percentages are based on theweight of the solid support relative to the total weight of thecatalyst.

The titanated chromium supported catalyst can have any pore volume,surface area, and average particle size disclosed herein, such as atotal pore volume from about 0.5 to about 5 mL/g (or from about 1 toabout 4 mL/g), a BET surface area from about 200 to about 700 m²/g (orfrom about 200 to about 550 m²/g), and a d50 average particle size fromabout 10 to about 500 microns. Likewise, any suitable solid support canbe employed, non-limiting examples of which include silica,silica-alumina, silica-coated alumina, silica-titania,silica-titania-magnesia, silica-zirconia, silica-magnesia, silica-boria,aluminophosphate-silica, and the like, as well as any combinationthereof. An illustrative titanated chromium supported catalyst in whichthe solid support is silica can be referred to as a titanatedchromium/silica catalyst. The titanated chromium/silica catalyst,therefore, can comprise silica and from about 0.1 to about 15 wt. %chromium, from about 1 to about 10 wt. % titanium, and less than orequal to about 3 wt. % carbon, based on the total weight of the catalyst(or any respective amount of chromium, titanium, and carbon disclosedherein). At least about 75 wt. % of the chromium is present in anoxidation state of three or less, prior to activation/calcination.

Polymerization Processes

Titanated chromium supported catalysts of the present invention can beused to polymerize olefins to form homopolymers, copolymers,terpolymers, and the like. One such process for polymerizing olefins cancomprise contacting any (activated) titanated chromium supportedcatalyst disclosed herein (e.g., produced by any process disclosedherein) and an optional co-catalyst with an olefin monomer and anoptional olefin comonomer in a polymerization reactor system underpolymerization conditions to produce an olefin polymer.

The catalyst compositions and/or polymerization processes disclosedherein often can employ a co-catalyst. In some aspects, the co-catalystcan comprise a metal hydrocarbyl compound, examples of which includenon-halide metal hydrocarbyl compounds, metal hydrocarbyl halidecompounds, non-halide metal alkyl compounds, metal alkyl halidecompounds, and so forth, and in which the metal can be any suitablemetal, often a group 13 metal. Hence, the metal can be boron or aluminumin certain aspects of this invention, and the co-catalyst can comprise aboron hydrocarbyl or alkyl, or an aluminum hydrocarbyl or alkyl, as wellas combinations thereof.

In one aspect, the co-catalyst can comprise an aluminoxane compound, anorganoaluminum compound, or an organoboron compound, and this includescombinations of more than co-catalyst compound. Representative andnon-limiting examples of aluminoxanes include methylaluminoxane,modified methylaluminoxane, ethylaluminoxane, n-propylaluminoxane,iso-propylaluminoxane, n-butylaluminoxane, t-butylaluminoxane,sec-butylaluminoxane, iso-butylaluminoxane, 1-pentylaluminoxane,2-pentylaluminoxane, 3-pentyl aluminoxane, isopentylaluminoxane,neopentylaluminoxane, and the like, or any combination thereof.Representative and non-limiting examples of organoaluminums includetrimethylaluminum, triethylaluminum, tri-n-propylaluminum,tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum,tri-n-octylaluminum, diisobutylaluminum hydride, diethylaluminumethoxide, diethylaluminum chloride, and the like, or any combinationthereof. Representative and non-limiting examples of organoboronsinclude tri-n-butyl borane, tripropylborane, triethylborane, and thelike, or any combination thereof. Co-catalysts that can be used in thecatalyst compositions of this invention are not limited to theco-catalysts described above. Other suitable co-catalysts (such asorganomagnesiums and organolithiums) are well known to those of skill inthe art including, for example, those disclosed in U.S. Pat. Nos.3,242,099, 4,794,096, 4,808,561, 5,576,259, 5,807,938, 5,919,983,7,294,599 7,601,665, 7,884,163, 8,114,946, and 8,309,485, which areincorporated herein by reference in their entirety.

Unsaturated monomers that can be employed with catalyst compositions andpolymerization processes of this invention typically can include olefincompounds having from 2 to 30 carbon atoms per molecule and having atleast one olefinic double bond. This invention encompasseshomopolymerization processes using a single olefin such as ethylene orpropylene, as well as copolymerization, terpolymerization, etc.,reactions using an olefin monomer with at least one different olefiniccompound. For example, the resultant ethylene copolymers, terpolymers,etc., generally can contain a major amount of ethylene (>50 molepercent) and a minor amount of comonomer (<50 mole percent), though thisis not a requirement. Comonomers that can be copolymerized with ethyleneoften can have from 3 to 20 carbon atoms, or from 3 to 10 carbon atoms,in their molecular chain.

Acyclic, cyclic, polycyclic, terminal (α), internal, linear, branched,substituted, unsubstituted, functionalized, and non-functionalizedolefins can be employed in this invention. For example, typicalunsaturated compounds that can be polymerized with the catalystcompositions of this invention can include, but are not limited to,ethylene, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene,1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,2-hexene, 3-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene,the four normal octenes (e.g., 1-octene), the four normal nonenes, thefive normal decenes, and the like, or mixtures of two or more of thesecompounds. Cyclic and bicyclic olefins, including but not limited to,cyclopentene, cyclohexene, norbornylene, norbornadiene, and the like,also can be polymerized as described herein. Styrene can also beemployed as a monomer in the present invention. In an aspect, the olefinmonomer can comprise a C₂-C₂₀ olefin; alternatively, a C₂-C₂₀alpha-olefin; alternatively, a C₂-C₁₀ olefin; alternatively, a C₂-C₁₀alpha-olefin; alternatively, the olefin monomer can comprise ethylene;or alternatively, the olefin monomer can comprise propylene.

When a copolymer (or alternatively, a terpolymer) is desired, the olefinmonomer and the olefin comonomer independently can comprise, forexample, a C₂-C₂₀ alpha-olefin. In some aspects, the olefin monomer cancomprise ethylene or propylene, which is copolymerized with at least onecomonomer (e.g., a C₂-C₂₀ alpha-olefin, a C₃-C₂₀ alpha-olefin, etc.).According to one aspect of this invention, the olefin monomer used inthe polymerization process can comprise ethylene. In this aspect,examples of suitable olefin comonomers can include, but are not limitedto, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene,1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,2-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, 1-octene,1-decene, styrene, and the like, or combinations thereof. According toanother aspect of the present invention, the olefin monomer can compriseethylene, and the comonomer can comprise a C₃-C₁₀ alpha-olefin;alternatively, the comonomer can comprise 1-butene, 1-pentene, 1-hexene,1-octene, 1-decene, styrene, or any combination thereof; alternatively,the comonomer can comprise 1-butene, 1-hexene, 1-octene, or anycombination thereof; alternatively, the comonomer can comprise 1-butene;alternatively, the comonomer can comprise 1-hexene; or alternatively,the comonomer can comprise 1-octene.

Generally, the amount of comonomer introduced into a polymerizationreactor system to produce a copolymer can be from about 0.01 to about 50weight percent, based on the total weight of the monomer and comonomer.According to another aspect of the present invention, the amount ofcomonomer introduced into a polymerization reactor system can be fromabout 0.01 to about 40 weight percent comonomer, based on the totalweight of the monomer and comonomer, or alternatively, from about 0.1 toabout 35 weight percent comonomer, or from about 0.5 to about 20 weightpercent comonomer.

While not intending to be bound by this theory, where branched,substituted, or functionalized olefins are used as reactants, it isbelieved that a steric hindrance can impede and/or slow thepolymerization process. Thus, branched and/or cyclic portion(s) of theolefin removed somewhat from the carbon-carbon double bond would not beexpected to hinder the reaction in the way that the same olefinsubstituents situated more proximate to the carbon-carbon double bondmight.

According to one aspect of the present invention, at least onemonomer/reactant can be ethylene (or propylene), so the polymerizationreaction can be a homopolymerization involving only ethylene (orpropylene), or a copolymerization with a different acyclic, cyclic,terminal, internal, linear, branched, substituted, or unsubstitutedolefin. In addition, the catalyst compositions of this invention can beused in the polymerization of diolefin compounds including, but notlimited to, 1,3-butadiene, isoprene, 1,4-pentadiene, and 1,5-hexadiene.

The titanated chromium supported catalysts of the present invention areintended for any olefin polymerization method using various types ofpolymerization reactor systems and reactors. The polymerization reactorsystem can include any polymerization reactor capable of polymerizingolefin monomers and comonomers (one or more than one comonomer) toproduce homopolymers, copolymers, terpolymers, and the like. The varioustypes of reactors include those that can be referred to as a batchreactor, slurry reactor, gas-phase reactor, solution reactor, highpressure reactor, tubular reactor, autoclave reactor, and the like, orcombinations thereof. The polymerization conditions for the variousreactor types are well known to those of skill in the art. Gas phasereactors can comprise fluidized bed reactors or staged horizontalreactors. Slurry reactors can comprise vertical or horizontal loops.High pressure reactors can comprise autoclave or tubular reactors. Thesereactor types generally can be operated continuously. Continuousprocesses can use intermittent or continuous polymer product discharge.Polymerization reactor systems and processes also can include partial orfull direct recycle of unreacted monomer, unreacted comonomer, and/ordiluent.

Polymerization reactor systems of the present invention can comprise onetype of reactor in a system or multiple reactors of the same ordifferent type (e.g., a single reactor, dual reactor, more than tworeactors). For instance, the polymerization reactor system can comprisea solution reactor, a gas-phase reactor, a slurry reactor, or acombination of two or more of these reactors. Production of polymers inmultiple reactors can include several stages in at least two separatepolymerization reactors interconnected by a transfer device making itpossible to transfer the polymer resulting from the first polymerizationreactor into the second reactor. The polymerization conditions in one ofthe reactors can be different from the operating conditions of the otherreactor(s). Alternatively, polymerization in multiple reactors caninclude the manual transfer of polymer from one reactor to subsequentreactors for continued polymerization. Multiple reactor systems caninclude any combination including, but not limited to, multiple loopreactors, multiple gas phase reactors, a combination of loop and gasphase reactors, multiple high pressure reactors, or a combination ofhigh pressure with loop and/or gas phase reactors. The multiple reactorscan be operated in series, in parallel, or both. Accordingly, thepresent invention encompasses polymerization reactor systems comprisinga single reactor, comprising two reactors, and comprising more than tworeactors. The polymerization reactor system can comprise a slurryreactor, a gas-phase reactor, a solution reactor, in certain aspects ofthis invention, as well as multi-reactor combinations thereof.

According to one aspect, the polymerization reactor system can compriseat least one loop slurry reactor, e.g., comprising vertical orhorizontal loops. Monomer, diluent, catalyst, and optional comonomer canbe continuously fed to a loop reactor where polymerization occurs.Generally, continuous processes can comprise the continuous introductionof monomer/comonomer, a catalyst, and a diluent into a polymerizationreactor and the continuous removal from this reactor of a suspensioncomprising polymer particles and the diluent. Reactor effluent can beflashed to remove the solid polymer from the liquids that comprise thediluent, monomer and/or comonomer. Various technologies can be used forthis separation step including, but not limited to, flashing that caninclude any combination of heat addition and pressure reduction,separation by cyclonic action in either a cyclone or hydrocyclone, orseparation by centrifugation.

A typical slurry polymerization process (also known as the particle formprocess) is disclosed, for example, in U.S. Pat. Nos. 3,248,179,4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191, 6,833,415, and8,822,608, each of which is incorporated herein by reference in itsentirety.

Suitable diluents used in slurry polymerization include, but are notlimited to, the monomer being polymerized and hydrocarbons that areliquids under reaction conditions. Examples of suitable diluentsinclude, but are not limited to, hydrocarbons such as propane,cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, andn-hexane. Some loop polymerization reactions can occur under bulkconditions where no diluent is used, such as can be employed in the bulkpolymerization of propylene to form polypropylene homopolymers.

According to yet another aspect, the polymerization reactor system cancomprise at least one gas phase reactor (e.g., a fluidized bed reactor).Such reactor systems can employ a continuous recycle stream containingone or more monomers continuously cycled through a fluidized bed in thepresence of the catalyst under polymerization conditions. A recyclestream can be withdrawn from the fluidized bed and recycled back intothe reactor. Simultaneously, polymer product can be withdrawn from thereactor and new or fresh monomer can be added to replace the polymerizedmonomer. Such gas phase reactors can comprise a process for multi-stepgas-phase polymerization of olefins, in which olefins are polymerized inthe gaseous phase in at least two independent gas-phase polymerizationzones while feeding a catalyst-containing polymer formed in a firstpolymerization zone to a second polymerization zone. One type of gasphase reactor is disclosed in U.S. Pat. Nos. 5,352,749, 4,588,790,5,436,304, 7,531,606, and 7,598,327, each of which is incorporated byreference in its entirety herein.

According to still another aspect, the polymerization reactor system cancomprise a high pressure polymerization reactor, e.g., can comprise atubular reactor or an autoclave reactor. Tubular reactors can haveseveral zones where fresh monomer, initiators, or catalysts are added.Monomer can be entrained in an inert gaseous stream and introduced atone zone of the reactor. Initiators, catalysts, and/or catalystcomponents can be entrained in a gaseous stream and introduced atanother zone of the reactor. The gas streams can be intermixed forpolymerization. Heat and pressure can be employed appropriately in suchhigh pressure polymerization reactors to obtain optimal polymerizationreaction conditions.

According to yet another aspect, the polymerization reactor system cancomprise a solution polymerization reactor, wherein themonomer/comonomer can be contacted with the catalyst composition bysuitable stirring or other means. A carrier comprising an inert organicdiluent or excess monomer can be employed. If desired, themonomer/comonomer can be brought in the vapor phase into contact withthe catalytic reaction product, in the presence or absence of liquidmaterial. The polymerization zone can be maintained at temperatures(e.g., up to between 150° C. and 180° C.) and pressures that will resultin the formation of a solution of the polymer in a reaction medium.Agitation can be employed to obtain better temperature control and tomaintain uniform polymerization mixtures throughout the polymerizationzone. Adequate means are utilized for dissipating the exothermic heat ofpolymerization.

In some aspects, the polymerization reactor system can comprise anycombination of a raw material feed system, a feed system for catalystand/or catalyst components, and/or a polymer recovery system, includingcontinuous systems. In other aspects, suitable reactor systems cancomprise systems for feedstock purification, catalyst storage andpreparation, extrusion, reactor cooling, polymer recovery,fractionation, recycle, storage, loadout, laboratory analysis, andprocess control.

Polymerization conditions that can be monitored, adjusted, and/orcontrolled for efficiency and to provide desired polymer properties caninclude, but are not limited to, reactor temperature, reactor pressure,catalyst system flow rate into the reactor, monomer flow rate (andcomonomer, if employed) into the reactor, monomer concentration in thereactor, olefin polymer output rate, recycle rate, hydrogen flow rate(if employed), reactor cooling status, and the like. Polymerizationtemperature can affect catalyst productivity, polymer molecular weight,and molecular weight distribution. A suitable polymerization temperaturecan be any temperature below the de-polymerization temperature accordingto the Gibbs Free energy equation. Typically, this includes from about60° C. to about 280° C., for example, from about 60° C. to about 185°C., from about 60° C. to about 115° C., or from about 130° C. to about180° C., depending upon the type of polymerization reactor, the polymergrade, and so forth. In some reactor systems, the polymerization reactortemperature generally can be within a range from about 70° C. to about110° C., or from about 125° C. to about 175° C. Various polymerizationconditions can be held substantially constant, for example, for theproduction of a particular grade of olefin polymer.

Suitable pressures will also vary according to the reactor andpolymerization type. The pressure for liquid phase polymerizations in aloop reactor typically can be less than 1000 psig (6.9 MPa). Thepressure for gas phase polymerization usually can be in the 200 psig to500 psig range (1.4 MPa to 3.4 MPa). High pressure polymerization intubular or autoclave reactors generally can be conducted at about 20,000psig to 75,000 psig (138 MPa to 517 MPa). Polymerization reactors canalso be operated in a supercritical region occurring at generally highertemperatures and pressures (for instance, above 92° C. and 700 psig(4.83 MPa)). Operation above the critical point of apressure/temperature diagram (supercritical phase) can offer advantagesto the polymerization reaction process.

Aspects of this invention also are directed to olefin polymerizationprocesses conducted in the absence of added hydrogen. An olefinpolymerization process of this invention can comprise contacting atitanated chromium supported catalyst and an optional co-catalyst withan olefin monomer and optionally an olefin comonomer in a polymerizationreactor system under polymerization conditions to produce an olefinpolymer, and wherein the polymerization process is conducted in theabsence of added hydrogen (no hydrogen is added to the polymerizationreactor system). As one of ordinary skill in the art would recognize,hydrogen can be generated in-situ by certain catalyst systems in variousolefin polymerization processes, and the amount generated can varydepending upon the specific catalyst components employed, the type ofpolymerization process used, the polymerization reaction conditionsutilized, and so forth.

In other aspects, it may be desirable to conduct the polymerizationprocess in the presence of a certain amount of added hydrogen.Accordingly, an olefin polymerization process of this invention cancomprise contacting a titanated chromium supported catalyst and anoptional co-catalyst with an olefin monomer and optionally an olefincomonomer in a polymerization reactor system under polymerizationconditions to produce an olefin polymer, wherein the polymerizationprocess is conducted in the presence of added hydrogen (hydrogen isadded to the polymerization reactor system). For example, the ratio ofhydrogen to the olefin monomer in the polymerization process can becontrolled, often by the feed ratio of hydrogen to the olefin monomerentering the reactor. The amount of hydrogen added (based on the amountof olefin monomer) to the process can be controlled at a molarpercentage which generally falls within a range from about 0.05 to about20 mole %, from about 0.1 to about 15 mole %, from about 0.25 to about10 mole %, or from about 0.5 to about 10 mole %. In some aspects of thisinvention, the feed or reactant ratio of hydrogen to olefin monomer canbe maintained substantially constant during the polymerization run for aparticular polymer grade. That is, the hydrogen:olefin monomer ratio canbe selected at a particular ratio, and maintained at the ratio to withinabout +/−25% during the polymerization run. Further, the addition ofcomonomer (or comonomers) can be, and generally is, substantiallyconstant throughout the polymerization run for a particular polymergrade.

However, in other aspects, it is contemplated that monomer, comonomer(or comonomers), and/or hydrogen can be periodically pulsed to thereactor, for instance, in a manner similar to that employed in U.S. Pat.No. 5,739,220 and U.S. Patent Publication No. 2004/0059070, thedisclosures of which are incorporated herein by reference in theirentirety.

The concentration of the reactants entering the polymerization reactorsystem can be controlled to produce resins with certain physical andmechanical properties. The proposed end-use product that will be formedby the polymer resin and the method of forming that product ultimatelycan determine the desired polymer properties and attributes. Mechanicalproperties include tensile, flexural, impact, creep, stress relaxation,and hardness tests. Physical properties include density, molecularweight, molecular weight distribution, melting temperature, glasstransition temperature, temperature melt of crystallization, density,stereoregularity, crack growth, long chain branching, and rheologicalmeasurements.

This invention is also directed to, and encompasses, the polymersproduced by any of the polymerization processes disclosed herein.Articles of manufacture can be formed from, and/or can comprise, thepolymers produced in accordance with this invention.

Polymers and Articles

Olefin polymers encompassed herein can include any polymer produced fromany olefin monomer and optional comonomer(s) described herein. Forexample, the olefin polymer can comprise an ethylene homopolymer, anethylene copolymer (e.g., ethylene/α-olefin, ethylene/1-butene,ethylene/1-hexene, ethylene/1-octene, etc.), a propylene homopolymer, apropylene copolymer, an ethylene terpolymer, a propylene terpolymer, andthe like, including any combinations thereof. In one aspect, the olefinpolymer can be an ethylene/1-butene copolymer, an ethylene/1-hexenecopolymer, or an ethylene/1-octene copolymer, while in another aspect,the olefin polymer can be an ethylene/1-hexene copolymer.

If the resultant polymer produced in accordance with the presentinvention is, for example, an ethylene polymer, its properties can becharacterized by various analytical techniques known and used in thepolyolefin industry. Articles of manufacture can be formed from, and/orcan comprise, the olefin polymers (e.g., ethylene polymers) of thisinvention, whose typical properties are provided below.

Ethylene polymers produced in accordance with this invention can have ahigh load melt index (HLMI) of less than or equal to about 200, lessthan or equal to about 150, or less than or equal to about 100 g/10 min.Suitable ranges for the HLMI can include, but are not limited to, from 0to about 150, from about 1 to about 100, from about 1 to about 80, fromabout 2 to about 80, from about 4 to about 60, from about 8 to about 60,from about 1 to about 50, from about 3 to about 50, from about 3 toabout 40, or from about 6 to about 40 g/10 min.

The densities of ethylene-based polymers produced using the titanatedchromium supported catalysts and the processes disclosed herein oftenare greater than or equal to about 0.89 g/cm³. In one aspect of thisinvention, the density of the ethylene polymer can be in a range fromabout 0.90 to about 0.97 g/cm³. Yet, in another aspect, the density canbe in a range from about 0.91 to about 0.96 g/cm³, such as, for example,from about 0.92 to about 0.96 g/cm³, from about 0.93 to about 0.955g/cm³, or from about 0.94 to about 0.955 g/cm³.

In an aspect, ethylene polymers described herein can have a ratio ofMw/Mn, or the polydispersity index, of greater than or equal to about 5,greater than or equal to about 6, or greater than or equal to about 7.Often, the Mw/Mn can range up to about 30-40, therefore, non-limitingranges for Mw/Mn include from about 5 to about 40, from about 5 to about30, from about 5 to about 20, from about 6 to about 35, from about 6 toabout 30, from about 6 to about 20, from about 10 to about 30, fromabout 10 to about 25, from about 15 to about 40, or from about 15 toabout 25.

In an aspect, ethylene polymers described herein can have a ratio ofI₂₁/I₁₀ in a range from about 2 to about 10, from about 2 to about 9,from about 3 to about 10, from about 3 to about 9, or from about 3 toabout 8. In another aspect, ethylene polymers described herein can havea ratio of I₂₁/I₁₀ in a range from about 4 to about 10, from about 4 toabout 9, from about 5 to about 10, or from about 5 to about 7.

Polymers of ethylene, whether homopolymers, copolymers, and so forth,can be formed into various articles of manufacture. Articles which cancomprise polymers of this invention include, but are not limited to, anagricultural film, an automobile part, a bottle, a drum, a fiber orfabric, a food packaging film or container, a food service article, afuel tank, a geomembrane, a household container, a liner, a moldedproduct, a medical device or material, a pipe, a sheet or tape, a toy,and the like. Various processes can be employed to form these articles.Non-limiting examples of these processes include injection molding, blowmolding, rotational molding, film extrusion, sheet extrusion, profileextrusion, thermoforming, and the like. Additionally, additives andmodifiers are often added to these polymers in order to providebeneficial polymer processing or end-use product attributes. Suchprocesses and materials are described in Modern Plastics Encyclopedia,Mid-November 1995 Issue, Vol. 72, No. 12; and Film ExtrusionManual—Process, Materials, Properties, TAPPI Press, 1992; thedisclosures of which are incorporated herein by reference in theirentirety.

Also contemplated herein is a method for forming or preparing an articleof manufacture comprising a polymer produced by any of thepolymerization processes disclosed herein. For instance, a method cancomprise (i) contacting a titanated chromium supported catalyst (e.g.,produced as described herein) and an optional co-catalyst with an olefinmonomer and an optional olefin comonomer under polymerization conditionsin a polymerization reactor system to produce an olefin polymer; and(ii) forming an article of manufacture comprising the olefin polymer(e.g., having any of the polymer properties disclosed herein). Theforming step can comprise blending, melt processing, extruding, molding,or thermoforming, and the like, including combinations thereof.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, modifications, and equivalentsthereof, which after reading the description herein, can suggestthemselves to one of ordinary skill in the art without departing fromthe spirit of the present invention or the scope of the appended claims.

Melt index (MI, g/10 min) was determined in accordance with ASTM D1238at 190° C. with a 2.16 kg weight, I₁₀ (g/10 min) was determined inaccordance with ASTM D1238 at 190° C. with a 10 kg weight, and high loadmelt index (HLMI, I₂₁, g/10 min) was determined in accordance with ASTMD1238 at 190° C. with a 21.6 kg weight.

Catalyst Examples A-D Chromium Supported Catalysts and TitanatedChromium Supported Catalysts

Catalyst A was a commercial Cr/silica, having a surface area of 500 m²/gand a pore volume of 1.6 mL/g. While not tested, it is expected that atleast 99 wt. % of the chromium was present in an oxidation state ofthree or less. The catalyst was subsequently activated (calcined) in dryair for three hours at 650° C. Catalyst A was a control catalystcontaining 1 wt. % chromium, but no titanium.

Catalyst B was prepared by impregnating Catalyst A with 8 wt. % Ti as anacidic solution of TiOSO₄. Then, the acidic mixture was slowlyneutralized (over 4 hours) by dripping NH₄OH solution into the mixture.Next, the titanated catalyst was dried and subsequently activated at650° C. for three hours in dry air. Catalyst B was a control catalystusing a representative water-soluble titanium compound.

Catalyst C was prepared by impregnating Catalyst A with 2.5 wt. % Ti asa water-soluble titanium-silicon complex, followed by drying andsubsequent activation at 650° C. To make this titanium-silicon complex,52 g (0.25 mol) of tetraethyl orthosilicate were added to 140 g ofn-propanol, followed by 0.5 mL of a concentrated HCl solution. Then, 2.5mL (0.14 mol) of water were added and the mixture was warmed to 40° C.and stirred for 15 minutes. Then 35.5 g (0.125 mol) of titaniumtetraisopropoxide were added to the solution, followed by warming to 40°C. and stirring for another 20 minutes. There was no precipitate. Aclear solution was formed, which could then be added to water withoutprecipitation or gelation. Next, 30 mL of this clear solution were addedto 20 g of the Cr/silica catalyst (Catalyst A), resulting in a dampsand-like consistency, followed by the addition of 100 mL of water. Thislast water-addition step hydrolyzed the last residual alkoxy groups toleave a clean catalyst. While not tested, it is expected that thecatalyst contained significantly less than 1.5 wt. % carbon, and atleast 99 wt. % of the chromium was present in an oxidation state ofthree or less. The titanated catalyst was dried and subsequentlyactivated at 650° C. for three hours in dry air.

Catalyst D was prepared by impregnating Catalyst A with 2.5 wt. % Ti asa water-soluble titanium-silicon complex, followed by drying andsubsequent activation at 650° C. To make this titanium-silicon complex,104 g (0.5 mol) of tetraethyl orthosilicate were added to 200 g ofn-propanol, followed by 1 mL of concentrated HNO₃ solution. Then, 5 mL(0.28 mol) of water were added and the mixture was warmed to 40° C. andstirred for 15 minutes. Then, 71 g (0.25 mol) of titaniumtetraisopropoxide were added to the solution, followed by warming to 40°C. and stirring for another 20 min. There was no precipitate. A clearsolution was formed, which could then be added to water withoutprecipitation or gelation. Next, 16 mL of this clear solution were addedto 10 g of the Cr/silica catalyst (Catalyst A), resulting a dampsand-like consistency, followed by the addition of 100 mL of water. Thislast water-addition step hydrolyzed the last residual alkoxy groups toleave a clean catalyst. While not tested, it is expected that thecatalyst contained significantly less than 1.5 wt. % carbon, and atleast 99 wt. % of the chromium was present in an oxidation state ofthree or less. The titanated catalyst was dried and subsequentlyactivated at 650° C. for three hours in dry air.

Polymerization Experiments with Catalysts A-D Effect of Titanation onPolymer Melt Index

The chromium catalysts, prepared as described above, were used inpolymerization experiments conducted in a 2-L stainless steel reactor.Isobutane (1.2 L) was used in all runs. Approximately 50-100 mg of theactivated chromium catalyst was added through a charge port while slowlyventing isobutane vapor. The charge port was closed and the isobutanewas added. The contents of the reactor were stirred and heated to thedesired run temperature of 105° C., and ethylene was then introducedinto the reactor (no comonomer, hydrogen, or co-catalyst was used).Ethylene was fed on demand to maintain a reactor pressure of about 550psig, and each polymerization run was conducted for 50-135 minutes.Catalyst C and Catalyst D were evaluated at two different reaction timesand catalyst productivity's.

Table I summarizes the supported chromium catalyst used, melt flowproperties of the ethylene polymer produced (HLMI (I₂₁), I₁₀, and MI(I₂) are in units of g/10 min), and catalyst activities (g/g/hr) andproductivities (g/g) relating to the polymerization experiments.Unexpectedly, catalysts C and D (titanated chromium supported catalystsproduced in accordance with this invention) produced polymers havingsignificantly higher melt indices than that of catalyst A (no titanium),demonstrating the successful titanation procedure. Catalyst B was formedwith a common water-soluble titanium compound (TiOSO₄), but withoutsuccessful titanation, as shown by the polymers produced using CatalystA and Catalyst B having the same melt indices.

TABLE I Polymerization Summary. Catalyst Productivity Activity HLMI I₁₀MI HLMI/I₁₀ A 2,970 2,970 5.5 0.87 0 6.3 B 2,020 1,570 4.9 0.81 0 6.0 C1,100 1,290 14.6 2.66 0.08 5.5 C 1,930 860 15.0 2.88 0.10 5.2 D 3,2803,520 9.8 1.60 0.03 6.1 D 2,660 2,580 16.7 2.70 0.04 6.2

Constructive Example Titanating a Solid Support and Adding Chromium toProduce a Titanated Supported Catalyst

A titanated chromium supported catalyst can be prepared by impregnatinga solid support, such as silica (having a surface area of approximately400 m²/g and a pore volume of approximately 1.6 mL/g) with 2.5 wt. % Tias a water-soluble titanium-silicon complex, and with chromium, followedby drying. The titanium-silicon complex can be prepared as describedabove for the preparation of Catalyst C. Approximately 30 mL of thesolution containing the titanium-silicon complex can be mixed with 20 gof the silica solid support and a solution of chromium (III) acetate,followed by the addition of 100 mL of water (alternatively, the chromium(III) acetate can be added with the addition of the 100 mL of water).After drying, the titanated chromium/silica catalyst can contain 2.5 wt.% Ti and 1 wt. % Cr. It is expected that the catalyst containssignificantly less than 2 wt. % carbon, and at least 95 wt. % of thechromium is present in an oxidation state of three or less.

It is expected that the activated chromium/silica catalyst will producehigher melt index polymers, similar to those produced with Catalyst Cand Catalyst D, when tested under the same polymerization conditions.

The invention is described above with reference to numerous aspects andspecific examples. Many variations will suggest themselves to thoseskilled in the art in light of the above detailed description. All suchobvious variations are within the full intended scope of the appendedclaims. Other aspects of the invention can include, but are not limitedto, the following (aspects are described as “comprising” but,alternatively, can “consist essentially of” or “consist of”):

Aspect 1. A process for preparing a titanium-silicon complex, theprocess comprising:

(1) contacting a silicon compound with water and an acid or a base in asolvent to form a first solution containing a partially-hydrolyzedsilicon material; and

(2) contacting a titanium compound with the first solution containingthe partially-hydrolyzed silicon material to form a second solutioncontaining a titanium-silicon complex.

Aspect 2. The process defined in aspect 1, wherein the silicon compound,water, the acid or the base, and the solvent are combined in any order.

Aspect 3. The process defined in aspect 1, wherein the silicon compoundis contacted with the solvent, followed by addition of the acid or thebase, and then water to form the first solution.

Aspect 4. The process defined in any one of the preceding aspects,wherein a molar ratio of water to silicon (H₂O:Si) in step (1) is in anysuitable range or any range disclosed herein, e.g., from about 0.05:1 toabout 1.95:1, from about 0.1:1 to about 1.8:1, from about 0.2:1 to about1.5:1, from about 0.3:1 to about 1.2:1, from about 0.05:1 to about0.95:1, from about 0.1:1 to about 0.9:1, from about 0.2:1 to about0.8:1, from about 0.3:1 to about 0.7:1, etc.

Aspect 5. The process defined in any one of the preceding aspects,wherein the solvent is any suitable solvent or any solvent disclosedherein, e.g., the solvent is miscible with oil and water.

Aspect 6. The process defined in any one of the preceding aspects,wherein the solvent comprises a ketone (e.g., acetone), an alcohol(e.g., methanol, ethanol, n-propanol, isopropanol, etc.), a glycol, anester, an ether, acetonitrile, etc., or any combination thereof.

Aspect 7. The process defined in any one of the preceding aspects,wherein the silicon compound comprises any suitable silicon compound orany silicon compound disclosed herein, e.g., a silicon alkoxide (e.g.,tetraethyl orthosilicate), a silicon halide, a silicon hydride, asilane, a hydrocarbyl silane, a siloxane, etc., or any combinationthereof.

Aspect 8. The process defined in any one of aspects 1-7, wherein thesilicon compound, water, and the acid are contacted in the solvent instep (1), and the acid is any suitable acid or any acid disclosedherein, e.g., sulfuric acid, nitric acid, hydrochloric acid, hydrobromicacid, perchloric acid, sulfamic acid, etc., or any combination thereof.

Aspect 9. The process defined in any one of aspects 1-7, wherein thesilicon compound, water, and the base are contacted in the solvent instep (1), and the base is any suitable base or any base disclosedherein, e.g., ammonia, ammonium hydroxide, sodium hydroxide, magnesiumhydroxide, an alkyl-substituted ammonium hydroxide, an organic amine,etc., or any combination thereof.

Aspect 10. The process defined in any one of the preceding aspects,wherein a weight ratio of the acid or base to solvent (acid:solvent orbase:solvent) in step (1) is in any suitable range or any rangedisclosed herein, e.g., from about 1:5000 to about 1:10, from about1:2000 to about 1:20, from about 1:1000 to about 1:100, less than orequal to about 1:20, less than or equal to about 1:50, less than orequal to about 1:100, etc.

Aspect 11. The process defined in any one of the preceding aspects,wherein step (1) is conducted at any suitable temperature or atemperature in any range disclosed herein, e.g., from about 5° C. toabout 80° C., from about 15° C. to about 60° C., from about 20° C. toabout 50° C., etc.

Aspect 12. The process defined in any one of the preceding aspects,wherein a molar ratio of titanium to silicon (Ti:Si) in step (2) is inany suitable range or any range disclosed herein, e.g., from about 0.1:1to about 5:1, from about 0.1:1 to about 2:1, from about 0.2:1 to about3:1, from about 0.3:1 to about 2:1, from about 0.3:1 to about 1:1, fromabout 0.2:1 to about 0.9:1, etc.

Aspect 13. The process defined in any one of the preceding aspects,wherein the titanium compound comprises any suitable titanium compoundor any titanium compound disclosed herein, e.g., a Ti (III) compound, aTi (IV) compound, etc., or any combination thereof.

Aspect 14. The process defined in any one of the preceding aspects,wherein the titanium compound comprises any suitable titanium compoundor any titanium compound disclosed herein, e.g., a titanium alkoxide(e.g., titanium isopropoxide, titanium n-propoxide), a titanium halide,a titanium acetylacetonate, etc., or any combination thereof.

Aspect 15. The process defined in any one of the preceding aspects,wherein step (2) is conducted at any suitable temperature or atemperature in any range disclosed herein, e.g., from about 5° C. toabout 80° C., from about 15° C. to about 60° C., from about 20° C. toabout 50° C., etc.

Aspect 16. The process defined in any one of the preceding aspects,wherein the second solution containing the titanium-silicon complex doesnot contain a precipitate.

Aspect 17. A water-soluble titanium-silicon complex prepared by theprocess defined in any one of aspects 1-16.

Aspect 18. The process defined in any one of aspects 1-16, wherein theprocess further comprises a step of combining additional water and atleast a portion of the second solution containing the titanium-siliconcomplex to form a water-soluble titanium-silicon complex.

Aspect 19. The process defined in aspect 18, wherein the amount ofadditional water is an amount sufficient for complete hydrolysis of thetitanium-silicon complex.

Aspect 20. The process defined in aspect 18, wherein a molar ratio ofadditional water to silicon (H₂O:Si) in the combining step is in anysuitable range or any range disclosed herein, e.g., at least about 1:1,at least about 1.5:1, at least about 2:1, at least about 4:1, at leastabout 7:1, at least about 10:1, etc.

Aspect 21. A water-soluble titanium-silicon complex prepared by theprocess defined in any one of aspects 18-20.

Aspect 22. The process defined in any one of aspects 1-16 or 18-20,further comprising a step of (3) combining (mixing or slurrying) (in anyorder) at least a portion of the second solution containing thetitanium-silicon complex, a solid support, and optionally, additionalwater, and drying to form a titanated solid support.

Aspect 23. A process comprising combining (mixing or slurrying) (in anyorder) the water-soluble titanium-silicon complex defined in aspect 17or 21, a solid support, and optionally, additional water, and drying toform a titanated solid support.

Aspect 24. The process defined in aspect 22 or 23, wherein thetitanium-silicon complex is combined first with the solid support,followed by the additional water.

Aspect 25. The process defined in aspect 22 or 23, wherein thetitanium-silicon complex is combined first with the additional water,followed by the solid support.

Aspect 26. The process defined in any one of aspects 22-25, wherein theamount of additional water added is an amount sufficient for completehydrolysis of the titanium-silicon complex.

Aspect 27. The process defined in any one of aspects 22-26, wherein amolar ratio of additional water to silicon (H₂O:Si) in the combiningstep is in any suitable range or any range disclosed herein, e.g., atleast about 1:1, at least about 1.5:1, at least about 2:1, at leastabout 4:1, at least about 7:1, at least about 10:1, etc.

Aspect 28. The process defined in any one of aspects 22-27, wherein thecombining step is conducted at any suitable temperature or a temperaturein any range disclosed herein, e.g., from about 5° C. to about 80° C.,from about 15° C. to about 60° C., from about 20° C. to about 50° C.,etc.

Aspect 29. The process defined in any one of aspects 22-28, wherein thecombining step does not result in precipitation of the titanium-siliconcomplex.

Aspect 30. The process defined in any one of aspects 22-29, wherein thesolid support comprises any suitable solid oxide or any solid oxidedisclosed herein, e.g., silica, alumina, silica-alumina, silica-coatedalumina, aluminum phosphate, aluminophosphate, heteropolytungstate,titania, zirconia, magnesia, boria, zinc oxide, silica-titania,silica-zirconia, alumina-titania, alumina-zirconia, zinc-aluminate,alumina-boria, silica-boria, aluminophosphate-silica, titania-zirconia,etc., or any combination thereof.

Aspect 31. The process defined in any one of aspects 22-29, wherein thesolid support comprises silica, silica-alumina, silica-coated alumina,silica-titania, silica-titania-magnesia, silica-zirconia,silica-magnesia, silica-boria, aluminophosphate-silica, etc., or anycombination thereof.

Aspect 32. The process defined in any one of aspects 22-29, wherein thesolid support is silica.

Aspect 33. The process defined in any one of aspects 22-29, wherein thesolid support comprises a zeolite.

Aspect 34. The process defined in any one of aspects 22-33, wherein theamount of titanium in the titanated solid support is any suitable amountor an amount in any range disclosed herein, e.g., from about 0.1 toabout 20 wt. %, from about 0.5 to about 15 wt. %, from about 1 to about10 wt. %, from about 1 to about 6 wt. %, etc., based on the total weightof the titanated solid support.

Aspect 35. The process defined in any one of aspects 22-34, whereindrying comprises spray drying.

Aspect 36. The process defined in any one of aspects 22-35, furthercomprising a step of (4) calcining the titanated solid support.

Aspect 37. The process defined in any one of aspects 22-36, wherein thetitanated solid support has a pore volume (total) in any suitable range,or any range disclosed herein, e.g., from about 0.5 to about 5 mL/g,from about 1 to about 5 mL/g, from about 1 to about 3 mL/g, from about1.2 to about 2.5 mL/g, etc.

Aspect 38. The process defined in any one of aspects 22-37, wherein thetitanated solid support has a BET surface area in any suitable range, orany range disclosed herein, e.g., from about 200 to about 700 m²/g, fromabout 250 to about 550 m²/g, from about 275 to about 525 m²/g, etc.

Aspect 39. The process defined in any one of aspects 22-38, wherein thetitanated solid support has an average (d50) particle size in anysuitable range, or any range disclosed herein, e.g., from about 10 toabout 500 microns, from about 25 to about 250 microns, from about 40 toabout 160 microns, etc.

Aspect 40. A titanated solid support prepared by the process defined inany one of aspects 22-39.

Aspect 41. The process defined in any one of aspects 1-39, wherein step(1) comprises contacting the silicon compound, water, the acid or thebase, and a chromium-containing compound in the solvent.

Aspect 42. The process defined in any one of aspects 1-39, wherein step(2) comprises contacting the titanium compound and a chromium-containingcompound with the first solution containing the partially-hydrolyzedsilicon material.

Aspect 43. The process defined in any one of aspects 22-39, wherein step(3) comprises combining (in any order) a chromium-containing compound,at least a portion of the second solution containing thetitanium-silicon complex, a solid support, and optionally, additionalwater, and drying.

Aspect 44. A process comprising combining the titanated solid supportdefined in aspect 40 and a chromium-containing compound, in water, anddrying.

Aspect 45. The process defined in any one of aspects 41-44, wherein thechromium-containing compound comprises any suitable chromium (II)compound or any chromium (II) compound disclosed herein, e.g., chromium(II) acetate, chromium (II) chloride, chromium (II) bromide, chromium(II) iodide, chromium (II) sulfate, etc., or any combination thereof.

Aspect 46. The process defined in any one of aspects 41-44, wherein thechromium-containing compound comprises any suitable chromium (III)compound or any chromium (III) compound disclosed herein, e.g., achromium (III) carboxylate, a chromium (III) napthenate, a chromium(III) halide, chromium (III) sulfate, chromium (III) nitrate, a chromium(III) dionate, etc., or any combination thereof.

Aspect 47. The process defined in any one of aspects 41-44, wherein thechromium-containing compound comprises any suitable chromium (III)compound or any chromium (III) compound disclosed herein, e.g., chromium(III) acetate, chromium (III) acetylacetonate, chromium (III) chloride,chromium (III) bromide, chromium (III) sulfate, chromium (III) nitrate,etc., or any combination thereof.

Aspect 48. The process defined in any one of aspects 41-44, wherein thechromium-containing compound is soluble in the solvent.

Aspect 49. The process defined in aspect 48, wherein thechromium-containing compound comprises any suitable chromium-containingcompound or any chromium-containing compound disclosed herein, e.g.,tertiary butyl chromate, a diarene chromium (0) compound,bis-cyclopentadienyl chromium (II), chromium (III) acetylacetonate,chromium acetate, etc., or any combination thereof.

Aspect 50. The process defined in any one of aspects 41-44, wherein thechromium-containing compound is soluble in water.

Aspect 51. The process defined in aspect 50, wherein thechromium-containing compound comprises any suitable chromium-containingcompound or any chromium-containing compound disclosed herein, e.g.,chromium trioxide, chromium acetate, chromium nitrate, etc., or anycombination thereof.

Aspect 52. A titanated chromium supported catalyst produced by theprocess defined in any one of aspects 41-51.

Aspect 53. The process defined in any one of aspects 1-16 or 18-20,further comprising a step of (3) combining (mixing or slurrying) (in anyorder) at least a portion of the second solution containing thetitanium-silicon complex, a supported chromium catalyst, and optionally,additional water, and drying.

Aspect 54. A process comprising combining (mixing or slurrying) (in anyorder) the water-soluble titanium-silicon complex defined in aspect 17or 21, a supported chromium catalyst, and optionally, additional water,and drying.

Aspect 55. The process defined in aspect 53 or 54, wherein thetitanium-silicon complex is combined first with the supported chromiumcatalyst, followed by the additional water.

Aspect 56. The process defined in aspect 53 or 54, wherein thetitanium-silicon complex is combined first with the additional water,followed by the supported chromium catalyst.

Aspect 57. The process defined in any one of aspects 53-56, wherein theamount of additional water added is an amount sufficient for completehydrolysis of the titanium-silicon complex.

Aspect 58. The process defined in any one of aspects 53-57, wherein amolar ratio of additional water to silicon (H₂O:Si) in the combiningstep is in any suitable range, or any range disclosed herein, e.g., atleast about 1:1, at least about 1.5:1, at least about 2:1, at leastabout 4:1, at least about 7:1, at least about 10:1, etc.

Aspect 59. The process defined in any one of aspects 53-58, wherein thecombining step is conducted at any suitable temperature or a temperaturein any range disclosed herein, e.g., from about 5° C. to about 80° C.,from about 15° C. to about 60° C., from about 20° C. to about 50° C.,etc.

Aspect 60. The process defined in any one of aspects 53-59, wherein thecombining step does not result in precipitation of the titanium-siliconcomplex.

Aspect 61. The process defined in any one of aspects 53-60, whereindrying comprises spray drying.

Aspect 62. The process defined in any one of aspects 53-61, wherein thesupported chromium catalyst comprises chromium/silica,chromium/silica-titania, chromium/silica-titania-magnesia,chromium/silica-alumina, chromium/silica-coated alumina,chromium/aluminophosphate, etc., or any combination thereof.

Aspect 63. A titanated chromium supported catalyst produced by theprocess defined in any one of aspects 53-62.

Aspect 64. A process comprising thermally treating the titanatedchromium supported catalyst defined in aspect 52 or 63.

Aspect 65. An activated titanated chromium supported catalyst producedby the process defined in aspect 64.

Aspect 66. The process defined in any one of aspects 1-39, furthercomprising a step of contacting the titanated solid support with achromium-containing compound (e.g., chromium (III) acetate, basicchromium (III) acetate, chromium (III) acetylacetonate, Cr₂(SO₄)₃,Cr(NO₃)₃, and/or CrO₃) while thermally treating to form an activatedtitanated chromium supported catalyst.

Aspect 67. An activated titanated chromium supported catalyst producedby the process defined in aspect 66.

Aspect 68. The process defined in aspect 64 or 66, wherein thermallytreating comprises any suitable temperature and time conditions or anytemperature and time conditions disclosed herein, e.g., from about 400°C. to about 1000° C., from about 500° C. to about 900° C., from about550° C. to about 850° C., etc., for a time period of from about 1 min toabout 24 hr, from about 1 hr to about 12 hr, from about 30 min to about8 hr, etc.

Aspect 69. The catalyst defined in any one of aspects 52, 63, 65, or 67,wherein the amount of chromium in the catalyst is any suitable amount oran amount in any range disclosed herein, e.g., from about 0.1 to about20 wt. %, from about 0.5 to about 15 wt. %, from about 0.5 to about 10wt. %, from about 1 to about 6 wt. %, etc., based on the total weight ofthe catalyst.

Aspect 70. The catalyst defined in aspect 69, wherein the amount oftitanium in the catalyst is any suitable amount or an amount in anyrange disclosed herein, e.g., from about 0.1 to about 20 wt. %, fromabout 0.5 to about 15 wt. %, from about 1 to about 10 wt. %, from about1 to about 6 wt. %, etc., based on the total weight of the catalyst.

Aspect 71. The catalyst defined in aspect 69 or 70, wherein the catalysthas a pore volume (total) in any suitable range, or any range disclosedherein, e.g., from about 0.5 to about 5 mL/g, from about 1 to about 5mL/g, from about 1 to about 3 mL/g, from about 1.2 to about 2.5 mL/g,etc.

Aspect 72. The catalyst defined in any one of aspects 69-71, wherein thecatalyst has a BET surface area in any suitable range, or any rangedisclosed herein, e.g., from about 200 to about 700 m²/g, from about 250to about 550 m²/g, from about 275 to about 525 m²/g, etc.

Aspect 73. The catalyst defined in any one of aspects 69-72, wherein thecatalyst has an average (d50) particle size in any suitable range, orany range disclosed herein, e.g., from about 10 to about 500 microns,from about 25 to about 250 microns, from about 40 to about 160 microns,etc.

Aspect 74. The catalyst defined in any one of aspects 69-73, wherein thecatalyst contains less than or equal to about 3 wt. % carbon, less thanor equal to about 2 wt. % carbon, less than or equal to about 1 wt. %carbon, less than or equal to about 0.5 wt. % carbon, etc.

Aspect 75. An olefin polymerization process, the process comprisingcontacting the activated titanated chromium supported catalyst definedin any one of aspects 69-74 and an optional co-catalyst with an olefinmonomer and an optional olefin comonomer in a polymerization reactorsystem under polymerization conditions to produce an olefin polymer.

Aspect 76. The olefin polymerization process defined in aspect 75,wherein a co-catalyst is used, and the co-catalyst comprises anysuitable co-catalyst or any co-catalyst disclosed herein, e.g., analuminoxane co-catalyst, an organoaluminum co-catalyst, an organoboronco-catalyst, etc., or any combination thereof.

Aspect 77. The olefin polymerization process defined in aspect 75 or 76,wherein the olefin monomer comprises any olefin monomer disclosedherein, e.g., any C₂-C₂₀ olefin.

Aspect 78. The olefin polymerization process defined in any one ofaspects 75-77, wherein the olefin monomer and the optional olefincomonomer independently comprise a C₂-C₂₀ alpha-olefin.

Aspect 79. The olefin polymerization process defined in any one ofaspects 75-77, wherein the olefin monomer comprises ethylene.

Aspect 80. The olefin polymerization process defined in any one ofaspects 75-79, wherein the catalyst is contacted with ethylene and anolefin comonomer comprising a C₃-C₁₀ alpha-olefin.

Aspect 81. The olefin polymerization process defined in any one ofaspects 75-80, wherein the catalyst is contacted with ethylene and anolefin comonomer comprising 1-butene, 1-hexene, 1-octene, or a mixturethereof.

Aspect 82. The olefin polymerization process defined in any one ofaspects 75-78, wherein the olefin monomer comprises propylene.

Aspect 83. The olefin polymerization process defined in any one ofaspects 75-82, wherein the polymerization reactor system comprises abatch reactor, a slurry reactor, a gas-phase reactor, a solutionreactor, a high pressure reactor, a tubular reactor, an autoclavereactor, or a combination thereof.

Aspect 84. The olefin polymerization process defined in any one ofaspects 75-83, wherein the polymerization reactor system comprises aslurry reactor, a gas-phase reactor, a solution reactor, or acombination thereof.

Aspect 85. The olefin polymerization process defined in any one ofaspects 75-84, wherein the polymerization reactor system comprises aloop slurry reactor.

Aspect 86. The olefin polymerization process defined in any one ofaspects 75-85, wherein the polymerization reactor system comprises asingle reactor.

Aspect 87. The olefin polymerization process defined in any one ofaspects 75-85, wherein the polymerization reactor system comprises 2reactors.

Aspect 88. The olefin polymerization process defined in any one ofaspects 75-85, wherein the polymerization reactor system comprises morethan 2 reactors.

Aspect 89. The olefin polymerization process defined in any one ofaspects 75-88, wherein the olefin polymer comprises any olefin polymerdisclosed herein.

Aspect 90. The olefin polymerization process defined in any one ofaspects 75-81 or 83-89, wherein the olefin polymer comprises an ethylenehomopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexenecopolymer, and/or an ethylene/1-octene copolymer.

Aspect 91. The olefin polymerization process defined in any one ofaspects 75-78 and 82-89, wherein the olefin polymer comprises apolypropylene homopolymer and/or a propylene-based copolymer.

Aspect 92. The olefin polymerization process defined in any one ofaspects 75-91, wherein the polymerization conditions comprise apolymerization reaction temperature in a range from about 60° C. toabout 120° C. and a reaction pressure in a range from about 200 to about1000 psig (about 1.4 to about 6.9 MPa).

Aspect 93. The olefin polymerization process defined in any one ofaspects 75-92, wherein the polymerization conditions are substantiallyconstant, e.g., for a particular polymer grade.

Aspect 94. The olefin polymerization process defined in any one ofaspects 75-93, wherein no hydrogen is added to the polymerizationreactor system.

Aspect 95. The olefin polymerization process defined in any one ofaspects 75-93, wherein hydrogen is added to the polymerization reactorsystem.

Aspect 96. The olefin polymerization process defined in any one ofaspects 75-95, wherein the olefin polymer has a density in any rangedisclosed herein, e.g., from about 0.90 to about 0.97, from about 0.92to about 0.96, from about 0.93 to about 0.955, from about 0.94 to about0.955 g/cm³, etc.

Aspect 97. The olefin polymerization process defined in any one ofaspects 75-96, wherein the olefin polymer has a HLMI in any rangedisclosed herein, e.g., from about 1 to about 80, from about 3 to about50, from about 8 to about 60, from about 6 to about 40 g/10 min, etc.

Aspect 98. The olefin polymerization process defined in any one ofaspects 75-97, wherein the olefin polymer has a ratio of Mw/Mn in anyrange disclosed herein, e.g., from about 5 to about 40, from about 10 toabout 25, from about 15 to about 35, etc.

Aspect 99. The olefin polymerization process defined in any one ofaspects 75-98, wherein the olefin polymer has a ratio of I₂₁/I₁₀ in anyrange disclosed herein, e.g., from about 3 to about 8, from about 4 toabout 9, from about 5 to about 7, etc.

Aspect 100. An olefin polymer produced by the olefin polymerizationprocess defined in any one of aspects 75-99.

Aspect 101. An article of manufacture comprising the polymer defined inaspect 100.

Aspect 102. The article defined in aspect 101, wherein the article is anagricultural film, an automobile part, a bottle, a drum, a fiber orfabric, a food packaging film or container, a food service article, afuel tank, a geomembrane, a household container, a liner, a moldedproduct, a medical device or material, a pipe, a sheet or tape, or atoy.

Aspect 103. A titanated chromium supported catalyst comprising a solidsupport and from about 0.1 to about 15 wt. % chromium, from about 1 toabout 10 wt. % titanium, and less than or equal to about 3 wt. % carbon,based on the total weight of the catalyst; wherein at least about 75 wt.% of the chromium is present in an oxidation state of three or less.

Aspect 104. The catalyst defined in aspect 103, wherein the catalystcontains any suitable amount of chromium or an amount in any rangedisclosed herein, e.g., from about 0.5 to about 15 wt. %, from about 0.5to about 5 wt. %, from about 0.5 to about 2.5 wt. %, etc., based on thetotal weight of the catalyst.

Aspect 105. The catalyst defined in aspect 103 or 104, wherein thecatalyst contains any suitable amount of titanium or an amount in anyrange disclosed herein, e.g., from about 1 to about 8 wt. %, from about1 to about 6 wt. %, from about 1.5 to about 5 wt. %, etc., based on thetotal weight of the catalyst.

Aspect 106. The catalyst defined in any one of aspects 103-105, whereinthe catalyst contains less than or equal to about 2 wt. % carbon, lessthan or equal to about 1 wt. % carbon, less than or equal to about 0.5wt. % carbon, etc.

Aspect 107. The catalyst defined in any one of aspects 103-106, whereinthe catalyst has a pore volume (total) in any suitable range, or anyrange disclosed herein, e.g., from about 0.5 to about 5 mL/g, from about1 to about 5 mL/g, from about 1 to about 4 mL/g, from about 1.2 to about2.5 mL/g, etc.

Aspect 108. The catalyst defined in any one of aspects 103-107, whereinthe catalyst has a BET surface area in any suitable range, or any rangedisclosed herein, e.g., from about 200 to about 700 m²/g, from about 200to about 550 m²/g, from about 275 to about 525 m²/g, etc.

Aspect 109. The catalyst defined in any one of aspects 103-108, whereinthe catalyst has an average (d50) particle size in any suitable range,or any range disclosed herein, e.g., from about 10 to about 500 microns,from about 25 to about 250 microns, from about 40 to about 160 microns,etc.

Aspect 110. The catalyst defined in any one of aspects 103-109, whereinat least about 80 wt. %, at least about 90 wt. %, at least about 95 wt.%, etc., of the chromium is present in an oxidation state of three orless.

Aspect 111. The catalyst defined in any one of aspects 103-110, whereinthe solid support comprises any suitable solid oxide or any solid oxidedisclosed herein, e.g., silica, alumina, silica-alumina, silica-coatedalumina, aluminum phosphate, aluminophosphate, heteropolytungstate,titania, zirconia, magnesia, boria, zinc oxide, silica-titania,silica-zirconia, alumina-titania, alumina-zirconia, zinc-aluminate,alumina-boria, silica-boria, aluminophosphate-silica, titania-zirconia,etc., or any combination thereof.

1. A process for preparing a titanated chromium supported catalyst, theprocess comprising: (1) contacting a silicon compound with water and anacid or a base in a solvent to form a first solution containing apartially-hydrolyzed silicon material; (2) contacting a titaniumcompound with the first solution containing the partially-hydrolyzedsilicon material to form a second solution containing a titanium-siliconcomplex; and (3) combining a chromium-containing compound, at least aportion of the second solution containing the titanium-silicon complex,a solid support, and optionally, additional water, and drying to formthe titanated chromium supported catalyst.
 2. The process of claim 1,wherein in step (1): the silicon compound is contacted first with thesolvent, followed by addition of the acid or the base, and then water toform the first solution; and a molar ratio of water to silicon is in arange from about 0.1:1 to about 1.8:1.
 3. The process of claim 1,wherein in step (1): the solvent comprises an alcohol; the siliconcompound comprises a silicon alkoxide, a silicon halide, a siliconhydride, a silane, a hydrocarbyl silane, a siloxane, or any combinationthereof; and a molar ratio of water to silicon is in a range from about0.2:1 to about 0.8:1.
 4. The process of claim 1, wherein in step (2): amolar ratio of titanium to silicon is in a range from about 0.1:1 toabout 5:1; and the titanium compound comprises a titanium alkoxide, atitanium halide, a titanium acetylacetonate, or any combination thereof.5. The process of claim 1, wherein in step (2): a molar ratio oftitanium to silicon is in a range from about 0.3:1 to about 1:1; thetitanium compound is water-soluble; and the second solution containingthe titanium-silicon complex does not contain a precipitate.
 6. Theprocess of claim 1, wherein: the process further comprises a step ofcombining additional water with at least a portion of the secondsolution containing the titanium-silicon complex prior to step (3) toform a diluted second solution containing a hydrolyzed titanium-siliconcomplex, wherein the amount of additional water is an amount sufficientfor complete hydrolysis of the titanium-silicon complex; and step (3)comprising combining the chromium-containing compound, at least aportion of the diluted second solution containing the hydrolyzedtitanium-silicon complex, and the solid support, and drying to form thetitanated chromium supported catalyst.
 7. The process of claim 1,wherein in step (3): the titanium-silicon complex is combined with thesolid support before the additional water; and a molar ratio ofadditional water to silicon is at least about 2:1.
 8. The process ofclaim 1, wherein the solid support comprises silica, silica-alumina,silica-coated alumina, silica-titania, silica-titania-magnesia,silica-zirconia, silica-magnesia, silica-boria, aluminophosphate-silica,or any combination thereof.
 9. The process of claim 1, wherein: thesolid support comprises silica; and drying comprises spray drying. 10.The process of claim 1, wherein the chromium-containing compoundcomprises a water-soluble chromium (II) compound, a water-solublechromium (III) compound, or any combination thereof.
 11. The process ofclaim 1, wherein the titanated chromium supported catalyst contains:from about 0.5 to about 15 wt. % chromium; from about 1 to about 10 wt.% titanium; and less than 1 wt. % carbon; based on the total weight ofthe catalyst. 12-14. (canceled)
 15. A process for preparing a titanatedchromium supported catalyst, the process comprising: (1) contacting asilicon compound with water and an acid or a base in a solvent to form afirst solution containing a partially-hydrolyzed silicon material; (2)contacting a titanium compound with the first solution containing thepartially-hydrolyzed silicon material to form a second solutioncontaining a titanium-silicon complex; and (3) combining at least aportion of the second solution containing the titanium-silicon complex,a supported chromium catalyst, and optionally, additional water, anddrying to form the titanated chromium supported catalyst.
 16. Theprocess of claim 15, wherein in step (3): the titanium-silicon complexis combined with the supported chromium catalyst before the additionalwater; and a molar ratio of additional water to silicon is at leastabout 10:1.
 17. The process of claim 15, wherein the supported chromiumcatalyst comprises chromium/silica, chromium/silica-titania,chromium/silica-titania-magnesia, chromium/silica-alumina,chromium/silica-coated alumina, chromium/aluminophosphate, or anycombination thereof. 18-27. (canceled)
 28. The process of claim 1,wherein the titanated chromium supported catalyst comprises a titanatedchromium/silica catalyst.
 29. The process of claim 1, wherein the solidsupport comprises a zeolite.
 30. The process of claim 2, wherein: themolar ratio of water to silicon is in a range from about 0.2:1 to about0.8:1; and the solid support comprises silica, silica-alumina,silica-coated alumina, silica-titania, silica-titania-magnesia,silica-zirconia, silica-magnesia, silica-boria, aluminophosphate-silica,or any combination thereof.
 31. The process of claim 3, wherein: themolar ratio of water to silicon is in a range from about 0.3:1 to about0.7:1; and the solid support comprises silica, silica-alumina,silica-coated alumina, silica-titania, silica-titania-magnesia,silica-zirconia, silica-magnesia, silica-boria, aluminophosphate-silica,or any combination thereof.
 32. The process of claim 4, wherein: themolar ratio of titanium to silicon is in a range from about 0.3:1 toabout 1:1; and the solid support is silica.
 33. The process of claim 11,wherein the titanated chromium supported catalyst is characterized by: atotal pore volume from about 0.5 to about 5 mL/g; a BET surface areafrom about 200 to about 700 m²/g; and a d50 average particle size fromabout 10 to about 500 microns.
 34. The process of claim 15, wherein: amolar ratio of water to silicon in step (1) is in a range from about0.1:1 to about 1.8:1; a molar ratio of titanium to silicon in step (2)is in a range from about 0.1:1 to about 5:1; the silicon compoundcomprises a silicon alkoxide, a silicon halide, a silicon hydride, asilane, a hydrocarbyl silane, a siloxane, or any combination thereof;and the titanium compound comprises a titanium alkoxide, a titaniumhalide, a titanium acetylacetonate, or any combination thereof.
 35. Theprocess of claim 34, wherein the supported chromium catalyst compriseschromium/silica, chromium/silica-titania,chromium/silica-titania-magnesia, chromium/silica-alumina,chromium/silica-coated alumina, chromium/aluminophosphate, or anycombination thereof.
 36. The process of claim 15, wherein the titanatedchromium supported catalyst contains: from about 0.5 to about 15 wt. %chromium; from about 1 to about 10 wt. % titanium; and less than 1 wt. %carbon; based on the total weight of the catalyst.
 37. The process ofclaim 15, wherein the titanated chromium supported catalyst comprises atitanated chromium/silica catalyst.
 38. The process of claim 17, whereina molar ratio of water to silicon in step (1) is in a range from about0.2:1 to about 0.8:1.
 39. The process of claim 17, wherein a molar ratioof titanium to silicon in step (2) is in a range from about 0.3:1 toabout 1:1.
 40. The process of claim 17, wherein: the supported chromiumcatalyst comprises chromium/silica; and drying comprises spray drying.